Senior Year Ponies Up

Sunset thought her slight stagger getting off the bus was probably not visible. True to her word, Sonata had mounted her once full dark hit on the ride back to the city. Though enough of her load now lay in the bus's septic tank that her lover's belly wasn't noticeably distended, she still felt weak from the intensity of her several clandestine climaxes.

When she turned to look behind her at the recipient of those loads, though, Sonata's distress was entirely visible. She almost asked what was wrong, then realized.

"Oh. Sonata, you don't have anywhere to go, do you?"

Sonata shook her head.

"O-oh, don't be silly! I can go back to my place," she said. "I'm sure the others don't know anything's up!" Sunset knew she was attempting to smile, but only via context clues. She sighed.

"Don't be silly, Sonata. You shouldn't go back to people who've hurt you. You'd better stay with me."

"R-really?"

Sunset nodded.

"I told you I'd make sure you were safe. If you want to come to my place, you're welcome."

"Then I will." Sonata fell into step beside Sunset, walking towards the parking lot where her motorcycle waited. A moment later, "Thanks, Sunset." Then another moment later, she giggled, "I bet I'll cum at your place, too."

Sunset rolled her eyes, but couldn't suppress her grin. Still, as they walked to her motorcycle, Sonata still looked a little down.

"Something else up?" Sunset asked. Sonata was silent for a long moment.

"Um, I'm kind of worried about something. But I'm don't want to talk about it until I'm sure. Wasn't that new Twilight working on ways to detect magic?"

"Not working on, she's already got it. She used it on me a few days ago to see what kind of effect this spontaneous dick growth was having on me." She blushed remembering it.

"Oh! Do you, uh, think she'd use it on us?"

Sunset chuckled.

"I'm sure you just have to ask, that girl never met a data point she didn't like. You sure you don't wanna tell me what's up, though?"

Sonata nodded. "Can we go now?"

"If she's up for it, sure. Let me give her a call and see."

Twilight's phone rang to voice mail, but Sonata looked so crushed at the news that Sunset didn't want to just give up on it.

"She might have left her phone upstairs while doing lab work. She was worried for a while that the signals might interfere with her magic-detecting instruments. It's not far from my place, we can go by and see."

Sonata perked up and clung to Sunset's arm.

"Thanks, Sunset!"

Twilight's house was dark - Sunset wondered if her parents were ever home - but they walked around back and saw telltale cracks of dim light coming from the sides of the basement curtains and under the folding cellar door that served as Twilight's late night entrance and exit. Encouraged, Sunset knocked on the folding door.

For a long moment, there was no answer. Sunset knocked again. Just as she was about to leave, a faint "coming" echoed from below. A little while later, the door opened with a mechanical whir, Twilight having automated it some time ago. The skinny girl stood framed by the light spilling out from behind her. Her normally orderly hair was frazzled, and she wore her pajamas askew.

"Hey Sunset," she said brightly, then turned to Sonata and blushed. "Oh, and Sonata, what a surprise."

Sonata couldn't suppress a giggle, and Sunset had to fight it down.

"Uh, Twilight, you've got something..." Sunset gestured to the left side of her mouth, in the location where a strand of what looked like cum was sitting on Twilight's face. Her friend flushed royal purple.

"Oh." She wiped her finger over it, then licked it off. The taste seemed to make her realize what she'd done, and she somehow managed to blush even harder.

"I hope we're not interrupting," Sunset said. "Sonata came to me on our trip because she's worried the other Dazzlings are going to try something against us. She's hoping you'll do some tests on her."

Twilight took a moment to find her voice, but eventually did so.

"Oh! Well I was uh, doing some experiments with Rarity, but we're mostly finished. And I have news for you anyway, so you might as well come down." She turned below and called, "Rarity, Sunset and Sonata are here."

"Oh, do show them down," Rarity's voice echoed back.

Shrugging, Twilight walked back down the stairs, and the other two girls followed, the door closing with another whir behind them.

Twilight's lab reeked of sex. If the semen on her face hadn't made the nature of the experiments clear, the smell would have. Well, that and Rarity's state. The ivory-skinned beauty was lying on the bed-cum-exam-table, completely naked. Her belly was slightly swollen, and she wore a devilish expression.

"Oh so good to see you Sunset! As you can tell, we were advancing the cause of science. And Sonata too! What brings you here?"

Quickly the two went over the trip. Given the company, they didn't see much need to leave out the steamy details, especially since Rarity specifically asked.

"So, what do you want me to do, then?" Twilight asked.

"See how magical Sunset is, and how magical I am," Sonata said.

Twilight nodded. "Deal, but only if you tell me what you're worried about after."

"Deal."

The scans took about fifteen minutes for each of them. Rather than just using Ethyl 2, Twilight ran as many instruments over each of them as she had the last time Sunset was here. Rarity watched keenly, if distractingly. In the end, Sunset's magic was the same as always. Surprisingly, though, Sonata showed some - almost as much as one of the Rainbooms did when they ponied up.

"How did that happen?" Twilight looked at her screen, scratching her head. "I thought only your gems let you use magic."

"They let us capture it," Sonata said. "But we're not humans, we're magical. If we were in Equestria, we'd use the magic that's all over the world, just like land ponies. The gems just let us get more in different ways. And they let us do it here, where there isn't any magic to get from the world. But now I have some."

"Wherever did you get it, dear?" Rarity asked.

Sunset blushed. "I spent the whole trip pumping it into her. Is that what you realized, Sonata?"

Sonata nodded. "When Sunset and I first slept together, I felt a little spark or something. I didn't know what it meant at the time, but then I felt it again every time."

"But wait, why'd you get my magic tested, then?"

Sonata looked down at her feet.

"I wanted to be sure. I wasn't trying to use my magic on you, but I really like you. You've been so nice to me! But then I worried maybe it was my magic. I was worried maybe I'd made you like me without meaning to."

"This is enough magic to do...that?" Twilight asked.

"I don't think so," Sonata said. "But I was a bit worried."

Sunset hugged her. "You've never really had a friend, huh? Other than the other Dazzlings, anyway."

Sonata shook her head.

"Well, it's real, I promise." Sunset thought for a bit, then she swore.

"Sonata, do you feel like the magic's stronger than it was earlier?"

"Oh yeah. But then, you keep giving me more." She giggled.

"No I mean than like, when we got off the bus."

"Oh...maybe?"

"Why would it be?" Twilight asked. "How would she have more magic without getting any more, uh, put into her?"

"I guess I'm the only one who studied magical theory under Celestia," Sunset grinned at her silliness. "That's one of the things that makes magic, well, magical. It's anti-enropic. The best way to get more magic is to use it. When I use the potion and put magical semen into one of you, it doesn't do much, because your bodies can't metabolize or use it. So it just washes away, and eventually dissipates into such a low concentration that it's not doing anything. But Sonata can metabolize it just fine. She's not doing anything with it actively, but her body is, and it'll keep growing. If she used it, it might grow faster. Of course everyone has their limit on how much they can store, but she probably has a lot. I think that must be Adagio and Aria's plan."

"I think you lost me, I'm afraid," Rarity said.

"The potions! They must have found out about them. If they can get someone to fuck them with one of the potions, they'll get magic back in them. And once they do, it'll grow until they get some of their powers back again, just like Sonata did."

"Oh no," Twilight said, "that probably wouldn't be good. Let's warn the others." Sunset typed out a quick text message to the other girls, letting them know what was up and asking if any of them had given away potions.

"In the mean time," Twilight said, "I've learned a lot since I last saw you! First, I tested the semen I produced when I took the 'fertile' potion, and I don't think you need to worry about knocking anyone up. It's intensely magical and not human at all!"

"Wait, yours too? The nurse took a look at mine after an accident, I was worried I'd knocked up Muffins, but it was pony sperm. I thought I just made it because I got a pony cock, though?"

"Apparently not, mine was the same. It's still got some powerful magic, though. Even though it wasn't designed to work on humans, internal exposure of any kind magically causes the subject to advance to their most fertile instantaneously. So if you were to use it on a human and then she had sex with a human male, she'd almost certainly get pregnant."

"How did you figure that one out?"

"Oh, we tested that just before you arrived," Rarity purred. "Not only am I very satisfied, I'm also very fertile right now."

Everyone was silent for a moment.

"Wait a minute," Sonata said. "That's what the warm feeling was! I wasn't feeling magic, I was going into season! I forgot what it felt like, since this body doesn't usually do it."

Sunset looked at her. "Wait. How could that be? I was using the sterile potions. They had the blue label and everything."

"Dunno! But that's exactly what it felt like!"

Sunset felt a sudden coldness in her stomach, until she remembered the magical rainbow sperm. "Well, not like it matters since they're not the right sperm to knock anyone up."

"Nuh-uh! They're just not right to knock up humans!"

All the girls looked at Sonata, who was grinning like a girl who wasn't facing down an unplanned pregnancy.

"Twilight..." Sunset began.

"I don't know what a pregnant siren would even look like, in terms of readings. Besides, if they're anything like humans, we wouldn't be able to tell for a while, until her body started showing hormonal changes."

"But you can tell the potion made me fertile, and we just did that," Rarity said.

"Right, and I could maybe tell if Sonata's fertile too, if she's got human-like signs," Twilight said. "But I wouldn't be confident, and we wouldn't know if the potion made her that way, or if she needs magic to breed, and so the magic itself enabled it."

"Oh yeah," Sonata said, "that could be it."

"I dunno," Sunset said, "it seems like a big coincidence. What if something's wrong with the potions?"

"We know the blue label ones aren't normally fertile," Twilight said, "I did comparison tests. But maybe some got labeled wrong."

"I have a few on me still from this batch," Sunset said, "can you look at it under a microscope or something?"

Twilight shook her head. "As far as I can tell, both liquids are identical to all physical tests, and I'm nowhere near the level of analysis of magic I'd need to distinguish them. Either my instruments aren't precise enough, or the contraceptive spells and the fertility ones have the same kind of energy." She paused, and blushed. "The only test I know of is seeing if insemination causes fertility."

"Oooh," Sonata said, "that sounds fun!"

"Not for you, darling," Rarity said, "we can't tell if you're fertile or not. Besides, you might already be."

"I guess I'm not..." Sunset said.

"Right, but you might have the same problem as Sonata," Twilight said. "If the mirror didn't change enough of your internal anatomy, one of us inseminating you might get you pregnant. But...I'm not fertile right now." She was blushing furiously, but Sunset could see her large nipples, hard through her thin pajama top. As she watched Twilight unbuttoned the top two buttons, letting her tiny breasts free.

"Oooh," Sonata said as she stripped, "nice."

Sunset's body agreed, and she felt her panties straining as her cock manifested inside them.

"Go get your potion, dear," Rarity said to Sunset as Twilight shed her top, "I'll make sure she's nice and ready for you."

Sunset went to her bag and pulled out one of the potions. Filled with doubt, she double checked. The label was certainly blue, and the Equestrian text on it certainly indicated it was safe. What could have gone wrong? Hopefully Sonata was just wrong. But there was only one way to find out. She quaffed the potion, feeling the tingling heaviness of additional semen in her balls, and turned back to the others.

Sonata had stripped, apparently in solidarity with Twilight and Rarity, both of whom were totally naked. Rarity was working between Twilight's legs as the purple pixie sat on the side of the bed, Rarity's own full ivory ass moving irresistibly as she did so. Sunset moved towards them. Rarity must have heard her, because she turned from the panting Twilight to grin at Sunset.

"All ready for you, darling. I must say she's very wet. And we also found something else interesting." She stood, revealing Twilight's prominent lavender cock and full balls, perched above her soaked pussy. "You aren't the only one who doesn't always need the potion." Rarity moved over and whispered in Sunset's ear, "if you get under her, I can take care of that."

Sunset nodded and grinned at her, and moved over to lie face-up on the bed. She put her hands around Twilight's waist and guided the slight girl to her ready cock, letting Twilight sink on to her with a sigh, facing Sunset. She looked up into Twilight's eyes and smiled at the look of bliss on her friend's face.

Then her line of sight was broken by Rarity's deliciously round rump, as the debauched fashionista lowered her own dripping pussy onto Twilight's ready cock. The extra weight pushed Twilight down hard on Sunset, and all three girls let out a moan as both cocks lodged as deeply as possible inside the eager pussies.

Rarity reached down and grasped Twilight's ass with both hands, pulling her up and down in time with her own thrusts. Each stroke pulled her beyond Sunset's medial ring, then brought her down to full hilt. She saw Rarity was bringing the same to herself. Sunset saw the purple cock nearly clear Rarity's body at each up stroke, Twilight's heavy balls jiggling, then saw Rarity's cheeks part as she lowered herself again. It was hypnotic, and made her want to ravish Rarity next.

Sonata also apparently enjoyed the show. Sunset noticed her standing next to the bed, running one hand on her nipples and the other between her legs, staring intently at the three-way coupling.

"Don't be silly," Sunset panted, and grabbed her hand, pulling her toward the bed. At first Sonata seemed confused, but when Sunset yanked one of her legs towards the other side of the bed, she caught on. Sonata spread herself above Sunset's face and began lowering her crotch. Sunset's nose filled with Sonata's heady musk, and she closed her eyes and extended her tongue to lick the siren's dripping slit.

The juices were heavenly. Sunset wasn't sure if it was a natural property of sirens, if she could taste the magic, or just if the knowledge Sonata might be carrying her child made her taste better, but she'd not had anything like it since Equestria. She eagerly went to work, scooping out the delicious nectar with her tongue, which also seemed to drive Sonata wild.

Sunset seemed to enter a timeless place. On her cock, Twilight rose and fell deliciously, her tight opening caressing the magical shaft from top to bottom. On her lips, Sonata squirmed. She could see nothing, feel nothing except her lovers. The tide of pleasure rose and rose, not concentrated and sudden like a simple fuck, but a whole-body, gradually rising tide, every moment just slightly better than the last, a dazzling panoply of smell, taste, and above all, touch.

Finally, distantly, she noticed Sonata's legs clenching around her face, noticed she was drinking even more nectar down. She noticed, too, that her flare seemed to have hardened, sealing Twilight's pussy tight. She felt a heavy weight, as if Rarity's legs had given out, and felt Twilight's balls pressed against her, twitching as if they were unloading seed.

Then the pleasure rose just a tiny bit more, and her balls were too. Her mouth was too busy to yell or pant, so she moaned. She felt the pressure build as her semen flooded Twilight, and her pleasure kept ticking up, bit by bit. She realized Twilight would have to move soon, that her seed couldn't drain into her lover's womb against gravity, but Rarity was still heavy on them, and Twilight's balls still twitched as she pumped more and more into Rarity.

Then, the pressure eased, and she realized the fullness had overcome gravity, and Twilight's womb was flooding with her seed. Twilight's potentially magically fertile womb, and her potentially magically fertile seed. She knew Twilight was sure the magical semen couldn't impregnate her human body, but Sunset wondered. After all, it was magic, right? And it was doing everything else to make sure they'd conceive, including bringing Twilight into season. So why not? She imagined Twilight on one of her arms, Sonata on the other, both grinning and obviously pregnant.

She moaned harder into Sonata's dripping pussy, lapping up the intoxicating liquid, and her seed surged harder into Twilight.

Finally, she felt a surge of seed on to her thighs as her cock vanished. All three of the other girls fell to the large bed next to her, panting. Twilight and Rarity's bellies were swollen. Sunset moaned, still somehow horny in the aftermath.

Twilight rose unsteadily and went to her work bench. She pricked herself with a needle, then ran the blood into a small instrument. After a moment, the computer let out a little beep.

"I'm fertile, all right," she said. "Sunset, I don't know how it happened, but that was the wrong potion."

Sunset didn't hear the rest of what Twilight said. She knew she should be worried, but Sonata immediately leaned down and whispered in her ear:

"I'm glad you're my stallion, Sunset."

It was too much. Her cock sprung forth again, and Sonata was on it immediately.

"Let's make sure it took," Sonata whispered.

Sunset knew she should stop, just in case it hadn't. But it was too much. Instead, she rolled over, pressing Sonata beneath her and plunging her cock all the way inside her, making sure the siren would take the full load. Next to them Rarity was lying on her back. She said something low and seductive that Sunset didn't process, one hand on her swollen belly, the other fingering her pussy. Sunset was about to promise Rarity she'd be next, when the bed shook as Twilight arrived, pressing her resummoned cock between Rarity's spread legs.

Sunset realized they were unlikely to discuss the findings fully until much, much later.