Avalanche from a Flurry

"What's wrong, dear?"

Twilight tore her eyes off of Starswirl dancing with Mistmane and glanced to Rarity, sitting on the bean bag chair next to her. "The solution we found yesterday didn't entirely work."

Rarity perked an eyebrow. "I thought it didn't work at all."

"Turns out the missing ingredient was age difference. But it wore off for me a few hours ago, and now I'm also obsessed with spreading my sperm all over everything."

Rarity observed, "You don't have that."

"Not until I've cast this spell I can't stop designing in my head. Anyway, I think the timing was suspiciously close to a day. I'm wondering - have you gone a day without kissing Spike?"

Rarity considered. "No."

Twilight nodded. "So, I guess we're fine if we just keep doing it more often than that. To check, can you two go a day without kissing? If you suddenly begin feeling the old thoughts again, that's important data."

Rarity nodded. "I'm sure we can do that."

"On the other hoof… I've spoken with one pony who appears to have been completely cured. I wonder how much she did. More than kissing, she said."

Rarity coughed. "Well. That raises the point I thought you wanted to talk with me about yesterday."

"Oh?" Twilight realized immediately after she said it what Rarity must mean.

"Well, Spike and I recently… advanced to more than kissing."

"I see. Is there any room at all for your physical relationship to become more intense?"

Rarity immediately nodded. "We haven't done anything which could risk conceiving a draconequus, if that's a thing we could do. What with the name and all, we were a little concerned. So, ah, do you know where they come from?"

"No, but I'm pretty sure it took some special magic, more than a dragon and a pony bonking. Don't fuck him on or while wearing any major magical artifacts, like, say, wearing an element or on the table. And don't get wrapped up in fertility magic within a few days after being with him unless you've used Sea Mane's Removal. Or you can petrify your eggs to be on the safe side, like I have. Hrm. No, that's a bit advanced for you, but I could do it for you. Other than that, go to town."

Rarity blinked. "That was simpler than I was expecting."

Twilight nodded. After a minute, she said, "Where are the kids, anyway? I'd like to renew my therapy."

"Well, there's Spike."

"That'd work, but… I think the thoughts leak. Where do you think I got the idea of getting my sperm all over everything?"

Rarity gulped. "Oh my. Now I'm not sure I want to go a day without kissing him."

"Please?"

Rarity took a deep breath and nodded. "I wonder what I'll be picking up from him…"

Twilight returned to her spell design for a minute, and had a sudden insight. "Oh my. This… I think I may have just figured out how to get Tempest a working horn. Have you seen her?"

Rarity shook her head. "Well, I'll leave you to that." She headed out to mingle again.

Twilight got up and headed upstairs. A knock on her door - "Come in." Twilight found Tempest lying on her belly on her bed, reading. She looked up and smiled lightly. "Twilight. To what do I owe the pleasure of your company?"

Twilight asked, "Have you been in here all day?"

"Not at all. I walked around town until it got dark. Saw the sights. Castle Everfree and the clubhouse there, Ghastly Gorge. Your school grounds are nice."

Twilight smiled. "Thanks. We actually designed that, unlike the castle and clubhouse. So, anyway, I had an idea on how to give you a working horn."

Tempest's eyes widened, and she held her breath.

"Years ago, I cast a spell to give Rarity wings."

Tempest nodded. "Butterfly wings. They weren't as strong as pegasus wings, and would have worn off after a day or so. Do you mean you can adapt the spell to give a horn, and greatly increase the duration?"

Twilight shook her head. "The main insight from that was, we don't need to repair your existing horn, just get you one that works. I was also working on another spell that is simpler, but similar. I think that if I get that working, I can then adapt it to making you a new permanent horn, that we'd probably put just in front of or just behind your existing horn. The mana pathways would reroute themselves over time, and your old horn would magically dry up. Unless you keep making lightning blasts, in which case you'd maintain both, I think. Very speculative, here."

Tempest swallowed, and sat up on the edge of the bed. "That is a very attractive plan. Is there anything I can do to help this along?"

"Well, you could be a test subject for the other spell."

Tempest nodded. "And what's that other spell?"

Twilight came close and put a hoof on Tempest's barrel, aiming back to her belly. "You'd grow a different highly sensitive vascular organ, which though not also bony, does get hard at times."

Tempest grinned knowingly. "You want to give me a cock. Temporarily?"

Twilight nodded. "There'll be a trigger to end the spell, like touching the back of your head with your hoof, or something else you wouldn't do by accident."

Tempest decided to needle her. "Did you want to give me a cock so I could fuck you with it?"

"I do need to do this test before I can give you a functional horn. That is the main thing. But if you want? Hmm." She stopped and considered. "Well, I like you and respect you and trust you, and I think you think the same of me. I don't think we're going to fall in love, and we don't need to interact constantly so if it does get weird there won't be a major problem, but if you drop by occasionally that won't be suspicious. So, we can be discreet. And you can't get me pregnant, so that's out of the way. So I guess the setup is pretty much ideal, so sure, if you want to. Do you?" She's the best except for my parents. They'd be better in every way.

As Twilight said that, Tempest had an increasing giggle. "I see you've thought this through. So, no question I'd do you. But as for this penis you say I'll have… If it's usable, and if I don't hate it? Sure, I can try. If not, I guess it'll just be the test."

Twilight nodded. "Sounds like I should just go ahead?"

Tempest blinked. "Here? Now? Do you need a circle or diagram or something?"

"Transformations are my specialty, and it's definitely under my power level, so a diagram wouldn't really help." Tempest shrugged. Twilight began casting, and noted, "You should start studying unicorn magic again, at least the theory. I think this is all going to work. Maybe not on the first try, but I think it will."

Tempest didn't say anything. She was focused on the tingling sensation between her legs. She lowered her head to look down, and saw Twilight's magic pulsing around her nethers. The tingling went away and she was left numb. "I can't feel anything."

"I anesthetized it. If I didn't, this would be unbelievably painful. Since I want it to last longer, I can't do the usual pop reform. Doing it slowly, it could last a month or longer per casting."

Tempest put her head between her forelegs and watched as her body's reshaping became visible. Her heart pounded - it was more freakily alarming than any fight she'd been in - she couldn't feel it happening, she couldn't react to what was happening properly if she couldn't feel it, and anyway, there was nothing she could do. She took deep breaths and fought down her fear, preventing panic from taking hold.

After twenty seconds, it was done. Her feeling suddenly returned. Her new highly erect penis grazed lightly against her legs. Her body mapping suggested to her that this was happening on her clitoris and her urethra. Which, she supposed, was probably the case, but part of her brain insisted that should be behind her, not under. But as she looked at it, matching up the sensation with what she was seeing, the feeling of displacement faded.

Twilight's head came into view under her barrel - she was examining her work. "How is it? How does it feel?"

Tempest shrugged. "I feel like I'm wearing furry underwear, but I'll probably get used to that."

"Can I lick it?"

Tempest blinked. "You're not even going to pretend to be scientific about this?"

Twilight gave her a flat stare. "I'll get to the science later. I learned this spell to have sex with, one way or another. So, can I lick it?"

Tempest was tempted to just say 'yes' but a grin crept across her face. She snarled, "If you ever want to see your friends again, princess, you'd better."

Twilight rolled her eyes. "Come on, I think this is a me-dominant scene. I'm the mad wizard who's modifying your body."

Tempest ran with it. "Oh no! Anything but sucking me off!"

Twilight's eyeroll intensified. "Or we could have the scene be that we're doing this because we're horny and convenient for each other. This has the benefit of being true."

Tempest acquiesced, and Twilight reached forward with her left hoof and pulled Tempest's new cock to the side so she could reach it without poking her in the belly with her horn.

"Ow! What are you doing?"

Twilight released it. "Sorry, I thought hooves were safe."

"It felt like it was made of rusty nails." She stepped back and rolled onto her bed.

Twilight came over and looked at it closely. She'd followed the diagrams and what she remembered of the few penises she'd seen, and tapped as best she could into the abstract form she was pretty sure attached to pony penises. And as far as she was concerned, she'd done a pretty good job!

Tempest twitched, and it jiggled. "You're breathing on it."

Twilight giggled, then got up on the bed between Tempest's lower legs and looked up to her. "I'm going to do more than that." This. I made this. It's like having a penis as my son, attached to a grown mare. So maybe I can trick my mind into buying it as incest, scratch that itch too? I made this! And it's here for me!

Twilight put out her tongue and slowly lowered her head, and put it just above the transition from the sheath to the shaft. Mindful of the sensitivity, she didn't move her tongue, just placed it. It shifted under her tongue as its erection went from subsiding to increasing once more.

Tempest bucked. "That's so intense. I can barely take it."

Twilight backed off. "I wonder why… should I tone it down somehow?"

"I'll just get used to it, if you keep going."

So Twilight put her tongue back on Tempest; she stiffened, arched her back, and after merely seconds began spasming, and she produced a tiny dot of semen. They stared at it, and at the slightly-shrinking penis. I guess I neglected the testes in my focus on the penis.

Tempest declared, "Once, I made fun of a guy for coming early. I take it back."

Twilight cocked her head. "Wait, I thought you are interested in mares? If both, maybe I should…"

"Nope, females for me. Didn't say he was doing me." She shuddered again. "That was… intense. More!"

Twilight raised an eyebrow. "You just came."

"MORE!"

Twilight shrugged and gingerly licked the penis. Tempest gritted her teeth and grunted. Twilight erected a soundproofing field around them, and considered how to continue. She crawled up a bit on Tempest and rubbed her chest against it.

Tempest howled and writhed until Twilight gave her a break. She panted out, "Turn around. It'll get weird if I can see your face."

Twilight stood, reared up, and pivoted. Then she lowered herself to press her vulva against the side of the shaft. Tempest grunted as if kicked, and tensed up everywhere. Twilight pulled forward a little. Tempest shuddered as she had before, in orgasm.

"Again." Twilight pushed back, and Tempest emitted a high-pitched shriek, her whole body vibrating.

"Again! Do I have to tell you every time?"

As Twilight pulled forward again, she said, "Given your reactions, I'm not sure it'd be a good idea to keep going without your okay." Tempest's hind legs thumped against the bed as she sucked in air desperately.

After two deep breaths, Tempest said, "I'm sorry, I didn't quite catch that."

Twilight repeated what she'd said with a wicked grin, as she pushed backward again. Tempest screamed, and this time as Twilight's rear came close, Tempest reached forward, pulled on her hips and pulled, pressing Twilight's vulva to her mouth.

Twilight gasped at the sudden manipulation, then stopped struggling and focused on what Tempest was doing. Tempest had not started subtly and gently like the books had suggested. She hungrily jammed her snout against Twilight, and with a feat of oral dexterity massaged Twilight's clitoris with her lower lip while licking around her vagina.

The books have a point, I think. I'm excited, but that was a bit abrupt. Anyway, I can't wait to see if I can do what she's doing, or if it's as hard as it feels like it is. Wish you were here, Mom. Oh wait! There's a penis here, but I didn't get rid of her usual equipment. Twilight lowered herself down, pressing down on the penis with her barrel, and leaned her head in to face Tempest's altered crotch. Urethra and clitoris and prepuce were gone, but the labia and vagina remained. Twilight tried to replicate the licking motion.

Her motions failed as Tempest squeezed her hip tighter and the sensation rose. Or maybe I can focus on receiving what she's sending me, and cover how to do it myself later. The waves of ecstasy reverberated through her, making her twitch, which with the penis pressed to her, was a perfectly adequate form of reciprocation - so adequate that she felt it pulse, and another splotch of liquid emerged against her belly, as Tempest let her head fall back; her only verbalization was a gurgle.

They lay still for a few seconds.

Tempest raised her head and said, "I think I've only got one more in me. Let's make it count. I want to fuck you."

Twilight gaped. "With your sensitivity?"

"It'll be glorious. This has been like a hard sparring match, but with no bruises. That'll be like only the good parts of being stabbed."

Twilight wasn't entirely sure what those might be, but she got up and carefully stepped off the bed. Tempest shivered one last time and rolled to her feet. Twilight looked over her shoulder. "Sorry about the face, but I want to see."

Tempest looked up from where she'd been focusing. "Didn't even notice. I've never done this before, and it's not so easy. I feel like I'm about to have to take some other taunts back."

"I could guide you."

"… yeah, that'd probably be a good idea."

Twilight made her telekinetic field as gentle as possible, pulling the penis on axis with her vagina. Tempest used it as feedback and did most of the moving herself. Then she slipped forward, making contact, then pressing into Twilight's soaking vagina.

This is it. I'm having sex with a pony. And nopony's going to figure it out. Or if they do, we can laugh it off. Oh yeah, holding a press conference about the rumors, and I get Tempest up there and show off her penis and then I lick it and she sends tiny spurts all over their notepads.

… you know, I might want to pay attention to how it feels. Okay… It's actually really nice! Not as if that's a surprise. I'd need an entirely new vocabulary to put it into words, though. It's just not comparable to other feelings.

Tempest gradually put more and more weight on Twilight's back, then stopped moving.

Twilight gave her a few seconds, then said, "Tempest? Was it too much, so you needed to stop to avoid coming too early?"

No response.

Twilight lifted the unconscious Tempest out and off of her, and put her on her bed. She suffused the entire room with Sea Mane's Removal, then released the soundproofing. She listened at the door - there were no hoofsteps in the hall.

Her heart was still going pretty hard, and she was dripping in the wrong places, so she went to her room and took a thirty second cold shower, and dried off.

Then back down to the party, such as it was.

Rainbow Dash zoomed up to her and poked her. "Hey, where've you been?"

"I had an idea on how to give Tempest a working horn. Turns out she's asleep."