Sunset was returning home from her lab at Canterlot High after spending most of the afternoon there. Rarity had asked if she could get a few hours of peace while her parents were taking Sweetie Belle, Apple Bloom and Scootaloo out for the afternoon and Sunset had decided she may as well go where she could do some work in peace as well.

‘Her’ lab is technically just one of the science labs but one of the walls was lined with machines and devices Sunset had built in her search for answers regarding magic and it’s workings in this world. The Friendship Games had helped redirect her focus to a more promising line of inquiry but she still needed to flesh out the theory.

As she arrived she noticed Rarity’s parent’s car wasn’t in the drive so they must still be out with the kids. She was rather glad of that, given what was in the bag she was carrying. She went in and heard Rarity playing her keytar in their room. As Sunset climbed the stairs, the music stopped and then started again with a few bars of a different song. Sunset stopped at the top of the stairs to listen as Rarity started playing and stopping again, repeating this with random segments from different songs.

Intrigued, Sunset crept towards the door, placing her bag gently on the floor, before silently turning the handle and creeping in. Rarity was playing in front of the mirror and was unable to see the door. Sunset had to stop for a second to make sure her eyes were working, Rarity was playing completely naked. Sunset had never seen her ponied up while naked and the floor length pony tail swinging as she played a few notes and struck a finishing pose was rather alluring. She crept forward until she was in striking distance and then lunged forward, grabbing one of Rarity’s pony ears. This got her a smack on the cheek from the neck of Rarity’s keytar as she jumped and turned to face her.

“What was that for!” shrieked Rarity as she de-ponied.

“Why? Did you nearly jump out of your pants?” asked Sunset with a massive smirk looking down at her bare legs.

“Well I may have done, or I could have broken your cheek or my keytar,” she said before calming herself . “Hello Darling, how was your day?”

“Mine was fine but I’m really interested in yours,” said Sunset stepping forward and placing her hands on her girlfriend’s bare hips, the keytar between them. “Did you feel anything like a wingasm there?”

“No Darling, I felt like some crazy person just snuck up on me,” said Rarity matter-of-factly. “And if you must know, I was changing when my eye caught the case and I felt I needed to play a little. It’s been a while since I’ve actually practised.” Sunset’s grin showed she didn’t fully believe her. “And I may have been trying out some finishing poses. Don’t tell Rainbow Dash after what I said about them being silly.”

“My lips are sealed.” She leaned in towards Rarity until her still very much open lips were a fraction away from Rarity’s. Rarity closed the tiny gap as she felt her knees weaken as Sunset’s tongue found hers. “Someone’s a little frisky,” she gasped as they parted.

“I’m standing in front of my beautiful, naked girlfriend,” pointed out Sunset.

“Fair point,” conceded Rarity as she leaned in for another kiss.

After twenty seconds of heaven, Rarity broke off the kiss and took off her keytar, placing it gently against the wall before turning back to face her frisky girlfriend. She spread her legs a little and ran two fingers between her already damp pussy lips. She sucked one finger clean herself and offered the other to Sunset who eagerly wrapped her lips around it and removed any trace of her lovers pre-cum.

“Before we go any further, I’ve something for you.” said Sunset with a grin. She grabbed the bag she left outside the door and went over to the bed. Rarity slipped in behind her, wrapping her arms round her girlfriend, making sure to leave Sunset’s arms free to get her present out. As Sunset pulled out a box with a large, padded clamp on it, Rarity leaned her chin on Sunset’s shoulder to get a better look.

“What is it?” she asked.

“Hold on,” said Sunset as she clamped it tightly to the headboard.

Rarity’s eyes widened when Sunset brought out the second piece. It was a metal rod ending in a ten inch long, one and a half inch in diameter dildo with a circular base to stop the metal road from being able to enter someone. She proceeded to screw it into the hole on the front of the box. “Sunset, have you made a sex machine?” asked Rarity tentatively.

With the machine assembled, Sunset spun around in Rarity’s arms to face her with a big grin. This was all the answer Rarity needed. She moved her hands down to Sunset’s ass and pulled her in tight as she kissed her.

“Have you tested it?” asked Rarity.

“Of course, everything works perfectly.”

“No Darling, I mean have you tested it,” clarified Rarity with a raised eyebrow.

“Oh, no I haven’t,” admitted Sunset.

At this Rarity let go of Sunset and bounced onto the bed, landing on all fours with her head up high, standing like the proud unicorn she is, with the dildo just a few inches behind her.

“Test away Darling,” proclaimed Rarity.

“I should maybe run you through the controls first,” suggested Sunset. She took the remote out of the bag as Rarity turned to sit cross legged on the bed facing her. “It’s got variable speed controlled from the left dial and variable vibration controlled from the right,” explained Sunset turning the speed up to its lowest setting.

Rarity watched as the rod began moving back almost to its fully retracted length in about three seconds before moving back out at the same pace.

“I thought that seemed reasonable for the lowest speed but feedback would be welcome,” said Sunset as she turned the dial up.

The dildo started thrusting significantly quicker, taking about half a second per stroke. Sunset then turned it to its maximum speed at which point it began moving so quick Rarity couldn’t even estimate the time for one thrust. She just started at it with her mouth hanging open in awe.

“It may be capable of going a little too quick,” said Sunset seeing Rarity’s open mouth.

“I think it could be rather fun,” said Rarity absentmindedly.

As Sunset turned the speed dial back down and then off, Rarity noticed an indentation in the head of the dildo. “What are these marks?” she asked as she leaned in to inspect it.

“Oh, I’m not too happy about that,” admitted Sunset. “I’d made a cast of my lips and when I cast the dildo it would have my lips on the head. It looks a little odd though”

“So it’s like your gorgeous lips will be kissing me deep inside?” said Rarity as she lowered her head to kiss the lips on the dildo. “It’s a wonderful idea Darling.”

“So do you want to test it?” asked Sunset.

“Definitely,” said Rarity giving Sunset a sultry look.

“I’d recommend some lube first,” advised Sunset bending down to the bottom drawer where they kept it and passing it to Rarity who squirted a dose onto the dildo and ran her hand along it to spread it out.

“I’m glad I never had a boyfriend,” mused Rarity as she gave the dildo a handjob to get a good coating of lube. “This kind of thing always seemed rather disgusting. I must thank you for not putting the usual equipment at the base as well, they’re just horrid looking.”

“Think how it looks to me,” said Sunset. She was glad stallions in Equestria didn't go around with those hanging out on show.

“It’s lucky I got to you first then,” whispered Rarity into her girlfriend’s ear.

“Extremely,” replied Sunset leaning in to kiss her girlfriend.

With the lube liberally applied, Rarity turned round again and stood on all fours ready to be entered.

“It’s fully retracted so if you back onto it so the head’s in you then it should stay in,” said Sunset.

Rarity moved back as Sunset directed the dildo into her damp pussy. With a nod from Rarity, Sunset turned it on and the dildo slowly slid into her. As it reached its full extension the circular base pushed her forward an inch as it pressed against her.

“The size is perfect, Darling,” groaned Rarity as it retracted. “A little faster if you would.”

Sunset turned the dial up to a medium speed, approximately a second per stroke. She turned the vibration dial up to about a third which caused a sharp gasp from Rarity.

“Oh, now that is wonderful,” she said as the combination of the base slapping against her clit and surprisingly powerful vibrations pushed her on.

Sunset placed the remote by Rarity’s hand and knelt beside the bed reaching under her girlfriend to toy with her clit. This caused Rarity’s head to drop as a satisfied moan escaped her. She then reached for the remote and turned the speed up to about eighty percent. Sunset had to move her hand away as the slapping of the dildo was hurting her knuckles. She instead spanked Rarity lightly on the ass before running her hands up her girlfriend’s spine towards her head, enjoying the view of her breasts swinging with every thrust.

“Are you enjoying it?” asked Sunset.

“That’s a very silly question,” squeaked Rarity before her head dropped again as she groaned in pleasure.

Sunset hopped up onto the bed and slid herself under her girlfriend to give those hanging mounds of wonder some attention. She took one nipple in her mouth to a very agreeable moan from Rarity before nipping it lightly between her teeth as she roughly grabbed the other. With a combination of kissing, sucking and licking Sunset lavished attention on the luckily nipple.

Rarity wanted to return the favour but Sunset was still fully dressed and if she moved her arms to bend down, Rarity was sure she would just collapse. Instead she closed her eyes and let the sensation from behind and below overcome her. The feeling of Sunset’s tongue flicking her nipple and the sensation from behind her were amazing, she was so close but she wanted something else to make her cum. “Let me eat you,” she moaned to Sunset.

Knowing she was already close, Sunset wasted no time jumping off the bed, kicking of her shoes and pulling her jeans and panties down before hopping back on, sliding her legs between Rarity's arms and positioning her sex under her desperate girlfriend’s open mouth. Rarity collapsed onto her wet pussy and immediately plunged her tongue inside to make sure that wonderful taste was what threw her over the edge. As Sunset’s taste flooded her mouth, she came.

Rarity did her best to keep eating Sunset but could only manage a few licks between groans of ecstasy as she was relentlessly pounded from behind. She ended up just lying on Sunset’s leg, unable to do anything else.

As she saw Rarity coming down from her orgasm, Sunset reached for the remote and reduced the speed of the dildo to let her recover a little. As soon as she could, and with no words exchanged, Rarity went back to Sunset’s pussy and started toying with her clit. As she did so, Sunset took her top and bra off so she could fully enjoy the situation.

Sunset was already quite far on from just having watched Rarity being done from behind, rocking forward with each thrust, and knew she wouldn’t last long under her lover’s expert tongue. She reached down and ran a hand through Rarity’s hair as she grabbed her own breast, pinching her nipple and slightly twisting it for it an added bust of pleasure.

With no warning, Rarity plunged three fingers into Sunset’s sodden pussy as she nipped her clit with her teeth. Sunset let out a very loud and very excited giggle followed by some equally loud and excited moans as she pressed her girlfriends head into her pussy where Rarity eagerly lapped up her lovers cum. She then had a choice now between staying where she was with the still very pleasurable slow thrusts and vibrations in her pussy or enjoying the wonders of her girlfriend’s body. After half a second’s of thought, it was a resounding victory for Sunset’s body. Rarity kissed Sunset’s clit and began kissing her way up Sunset’s stomach. She loved the way Sunset had done this to her with the best orgasm of her life and wanted to do it to her.

As she slinked her way up Sunset’s body, kissing her every inch, Sunset let out a giggle that is only ever heard from the sexually aroused. She reached down and ran her fingers through Rarity’s hair letting her hands move down her back as Rarity made her way up to her chest. The sensation of the slowly vibrating dildo sliding out of her pussy felt nearly as good as kissing the body beneath her.

As she approached Sunset’s chest, she ran her hands across her breasts and gently squeezed as her tongue circled around her girlfriends rock hard nipple before rapidly flicking her. This caused another very happy giggle from Sunset. Rarity moved over to Sunset’s other nipple and nipped it between her teeth causing Sunset to let out a yelp which quickly changed to a happy groan. Rarity nipped her again before giving her a kiss and moving on up toward her lovers lips.

When she reached Sunsets face, Sunset darted up and stole a kiss dragging a pleasured sigh with it. She looked down into Sunset’s eyes with a big smile on her face. “That was amazing,” purred Rarity.

“Mmm, it really was,” replied Sunset in a dreamy voice. “You’re so hot getting it from behind.”

“You like seeing me being fucked like a pony?” asked Rarity putting a lot of emphasis on ‘fucked’.

“I just love seeing you,” said Sunset with a gentle kiss for Rarity’s lips.

“Sunset?”

“Mmm?”

“Can you do magic as a human?” asked Rarity.

“No. Why?” Sunset was rather confused as this had long been established.

“Because any time you kiss me it feels like you’re giving me a little burst of pleasure. I just wondered if you secretly could do some little lust spell or something.”

“I can’t, it’s just my amazing body doing that,” joked Sunset as she ran her hands down to Rarity’s ass and squeezed gently. Rarity leaned in and kissed her again, Sunset could almost feel a little spark of lust as those wonderful lips met hers. “Did you enjoy your present?” she asked, still needing a little recovery time before going again.

“It’s the best thing anyone has ever made for me,” said Rarity, pressing herself into Sunset. “Can I use it when you’re not here?”

“You use our other toys so I can’t ban you from the Cum Machine.” Rarity raised an eyebrow at ‘Cum Machine’. “Or some other name,” added Sunset. “How about the In-and-Out-Vibrating-Orgasm Machine?”

“Oh!” shouted Rarity, ignoring that silly suggestion as she bounced off of Sunset and then the bed. “I’ve got a present for you too,” she trilled.

Sunset rolled over to watch her naked girlfriend walk over to the wardrobe, far more seductively than needed, before bending down with her ass in the air to retrieve a box.

“I was going to give them to you as an ensemble,” said Rarity coming back to the bed, “but I really would be better fitting you for the rest of it.”

Sunset took the box and opened it to reveal a pair of gold high heels with her Cutie Mark on the front and a flame design extension that would reach up the front of her legs almost to her knees.

“They’re the shoes you had when you were Daydream Shimmer,” explained Rarity. “I’ve got the first draft design of your dress but I need to take some measurements to get it right. The gloves and jewellery are at the Boutique all ready for you.”

“They’re beautiful,” was all Sunset could get out.

“Try them on,” said Rarity excitedly.

Sunset slipped the shoes on and stood up to model them for her excited girlfriend.

“Do they fit alright?” asked Rarity, loving her naked girlfriend in her new big heels making her legs look even more shapely. “I’ve not made many shoes before.”

“Perfect,” said Sunset sitting back down.

“There’s a second reason I wanted you to have something of Daydream Shimmer. To remind you that you are a good person.”

“I know I am,” said Sunset, wearing a mask so perfect only one person in two dimensions would be able to see through it. Unfortunately she was sitting next to that one.

“Darling, I know you still fear the old you. Do you think I haven’t seen you staring into nothing? That flash of shame when someone bring her up.”

“She will always be a part of me,” admitted Sunset, looking away from Rarity. “I’ve came to terms with it now and I’m glad I did what I did. I found an amazing group of friends and I fell in love with the most amazing girl.”

“Aww, you say the sweetest things,” cooed Rarity before leaning in and kissing Sunset in the cheek.

“I just worry that she’ll do something to hurt you.”

“Do you want to go to the Boutique tomorrow and I could fit you for your dress?” said Rarity changing the subject.

“Sounds fun,” said Sunset with a genuine, warm smile as she took her girlfriend’s hands.

“I don’t know if a golden, shimmery cape would be a good analogue for your wings or if it’ll look tacky,” admitted Rarity. “I’ll show you what I have in mind tomorrow." Sunset hugged her and held on. “I’ll always be here for you,” she said, stroking Sunset’s hair. “Have you eaten yet?”

“Nope, too busy making a sex machine.”

“Come on the, I’ll throw something together,” said Rarity getting up and looking at the sex machine attached to her headboard. “Could you make a double dildo attachment?”

The next day Sunset went back to her lab to fabricate the additions Rarity had suggested. She knew Rarity wanted a double attachment so she could be fucked in her pussy and ass simultaneously but Sunset had another idea to throw in as well. She’d got everything made in a couple of hours, and swiftly headed back home. Unfortunately they never had any time alone so test it out. The day after though, Sweetie Belle had a swimming lesson so they would get about an hour and half to themselves. Plenty time.

Once the rest of the family were gone, and they were sure they weren’t coming back for anything they’d forgot, Sunset and Rarity eagerly headed upstairs. As soon as their bedroom door was closed, Rarity strip off as Sunset got the pieces from below the bed. As she set about assembling the new attachment, Rarity undressed her, too impatient to wait.

With her girlfriend now naked as well, Rarity eager looked at her new toy. It wasn’t what she was expecting, an over/under arrangement, instead it was two dildos situated at either end of a long bar so two girls could be fucked together.

“I know it’s not what you asked for,” said Sunset seeing Rarity eyeing it, “but it’s reconfigurable so you can have a double penetration set up as well.”

“Not a problem Darling, this is so much better than my idea,” said Rarity as she absentmindedly fingered herself.

“This way we can both feel the exact same and cum together,” said Sunset, still defending her design. “The vibration can vary between the two but the thrust speed will obviously be the same.”

As Sunset finished the sentence, Rarity placed a hand against her cheek and kissed her deeply and passionately. Sunset could only respond in kind, wrapping her arms around her girlfriend and holding her tight.

“I want to see you cum,” said Rarity as she pulled away with a gasp.

Sunset stole one last kiss before getting the lube and applying to both dildos. With everything appropriately lubricated she took up position in front of the new dildo, which didn’t have any lip imprints in it, as Rarity did the same on the old one. They were fully retracted so they both had to just slip them in to get ready. Unbeknownst to Sunset, Rarity slipped hers into her ass with a quiet groan, it had been so long since she’d had anal.

“Ready?” asked Sunset as she placed the remote between them.

“Mmm, Ready," confirmed Rarity, gyrating on the head of the dildo.

Sunset turned the dial to start off slowly, letting herself loosen up a little as she still wasn’t used to penetration. As for Rarity, the big dildo pushing into her ass was a little too tight, she should maybe have loosened up first, but she wasn’t going to stop, she’d loosen up soon enough.

“Oooh, wow that’s big,” moaned Sunset as she felt the full length inside her.

“It is amazing,” agreed Rarity, the pressure in her ass with the full ten inches inside her truly was.

Sunset turned the vibration controls up to fifty percent with no warning which caused them both to yelp as the vibrations echoed through them. Sunset’s arms gave way beneath her and she collapsed into the mattress. Rarity could feel the warmth of the vibrations spread into her pussy but she was nowhere near Sunset’s level of debilitating pleasure.

Rarity reached for the remote and turned the speed up to seventy percent. Sunset was now unable to stop moaning as, for the first time in her life, she was being fucked hard, the base of the dildo slapping hard against her clit multiple times a second. Rarity had now loosened up and was enjoying the smacking against her ass, still on all fours, and just pleasantly warm inside.

“Cum with me,” gasped Sunset as she turned her head to face Rarity. “Please.”

Rarity was nowhere near cumming but she started to moan anyway. She reached over and took Sunset’s hand but Sunset could barely notice it. Her eyes were unfocused and her mouth was open with her tongue hanging out. Rarity knew that look, she did that when Applejack was using her.

As Sunset broke out into squeals of delight Rarity did so as well. She wasn’t proud of faking an orgasm but knew it would make Sunset’s even better to think they were sharing it. She let her arms give way under her and let out a deep, primal groan of pleasure. Sunset was just gasping now as the sensation’s continued unabated, the impact still running through her and the vibrations causing her entire body to tingle.

Rarity turned the vibrations down to the lowest setting and reduced the speed to about ten percent. Eventually Sunset recovered and got back up onto all fours as the machine continued to fuck her, keeping a nice warmth flowing through her body.

“That was amazing,” she said, still slightly short on breath.

“You’re amazing,” said Rarity as she moved forward off the dildo.

Sunset didn’t move forward but stayed still, letting herself get fucked. While Rarity did think the sight of her girlfriend like this was very hot, she had to say what was on her mind. “Seeing you cumming like that, I couldn’t help but be reminded of someone. Slut-me.”

“How do you mean?” asked Sunset, all interest in another orgasm lost at this she turned off the machine and sat facing Rarity.

“I don’t want you to get addicted to this kind of fast and cheap orgasm. I don’t want us just to be fucked by a machine and be done. I want to explore your body, to tease you towards it, to feel like I’m one with you.” She reached out and took Sunset’s hands, “I want to make love.”

“I want that too,” admitted Sunset as she realised Rarity was right. “This would cheapen what we have.”

The two girls smiled at each other.

“But we can keep it for very occasional use?” asked Sunset.

“Of course.”

“I was thinking if we were watching TV in bed one night we could just have it on at the slowest setting for a nice warmth then we can fool around afterwards,” said Sunset with a massive grin.

"Such a dirty girl," said Rarity pushing Sunset backwards and climbing on top of her. This was much better, the warmth of her body, the tingle of her touch. It always led to great things.

Author's Note

The 'In-and-Out-Vibrating-Orgasm Machine' is named using the naming convention of Leonard of Quirm, one of Discworld's greatest minds in any field you could name, apart from the field of interesting naming. Just felt I should explain the oddness, Sunset's a Terry Pratchett fan.