"As wild dogs?" grinned Shari.
"I thought you were a fox," shot back Tim.
"Well, yes; culpeos are called foxes, but genetically they're closer to wolves."
"Does it really matter? I mean --" Tim put a hand on her top right breast, looking coyly up at the culpeo. "Wolves or foxes, we all have the same needs right?"
"I guess." Shari licked his lips. "Damn you look so sexy like that." Blushing harder, she began to cover her mouth, but then stopped. Whether it was the new hormones, the added size, or just wish fulfillment, he felt confident. Why hold it back? Tim certainly didn't seem to mind.
"Do I?" She played with her nipple, then trailed her fingers down to her next breast, moaning softly at having an erogenous zone over what used to be a forgettably flat abdomen.
Shari huffed. "You tease."
"You're one to talk, with your rod hanging out ever since we got here."
"I couldn't help it!"
"Yeah, well..." Tim interrupted herself with a louder moan as she squeezed her breath. "Ma-aybe I can help it..." She sat up. "Maybe I could... taste it again?"
"Be my guest."
Tim shifted onto her knees and leaned forward. She took a deep breath, then buried her muzzle in Shari's loins and took a deeper breath. Then she began eagerly licking, starting with Shari's balls and working up over his sheath, his knot, up to his tip. Shari's breath hissed through his fangs, his body tensing, claws digging into the sheets.
"Damn Tim... that feels ... sooo-ooo... good."
"Mmm, you taste good." Tim sucked on his tip. "So good. If all boys taste like this... I wish I had been gay!"
Shari chuckled, then caught his breath. He stared down at Tim, the long snout probing his manhood, the full breasts swaying with her movement. He exhaled in a growl.
"Enough."
"Hm?" Tim looked up, tawny eyes inquisitive.
"I need... I need more than your tongue, Tim. I need... I want..." He remembered what Tim had said about feeling like a man. "I want to claim you. Inside."
Tim's eyes lit up and she got to her feet. "Okay!" Shari also got up, to give her more access to the bed. However, instead of lying down on it, Tim just bent over, her tail wagging furiously above her upturned ass.
"What... what are you doing...?" Even as Shari asked though, he felt his cock stiffen a little more, the bulbs at the base inflate. She shivered at the powerful feeling of rightness at having a female present herself like that. At having that ass -- as round and juicy as he'd imagined -- offered to him for his pleasure.
"I-I don't know; it just feels natural, I guess?" Tim looked over her shoulder. "I guess I can... lay on my back if you'd rather --"
"No." Shari licked her lips. He took a shuddering breath. This is so weird... This feeling... so strong... so HARD... "I... nrrng... I think I... like you like that." She couldn't resist any longer, setting her hand to his shaft and stroking along it, choking a moan as she felt more precum squeeze along the length and out the tip.
"Oh good!" Tim's tail started wagging, spreading even more of her maddening scent through the room. "I-I mean, uh..."
"Oh God, Tim! Your smell..." He stalked up behind the jackal, just barely resisting the urge to stoop down and stick her nose into Tim's female sex.
"Do you like it? I think you smell pretty good too. I mean... I think that's your smell... so masculine... so powerful...!" She wiggled her butt in the air, tantalising, making Shari grow even harder. He felt like his whole being was focused down there, straining to be set free, focused entirely on that female form. Her fists clenched.
"Like it? It makes me... want to mount you like a bitch!"
"Well; aren't I a bitch?"
Shari swallowed. "Technically. Maybe. Arrre..." The lusty growl permeating her voice unnerved her, yet exhilarated him at the same time. "Are you surrre you want --?"
"Yes, please, Shari! I -- I think I'm in heat. I don't know. I feel so empty... so... needy I..."
Heat. For a moment she was distracted by the thought of pregnancy, but she dismissed it. They were completely different species now, despite similar appearance.
"Okay." She stepped forward, putting a hand to his cock, smearing the pre over it before pointing it towards that thick-lipped, dripping opening. Okay, she repeated silently. I can do this. It's okay to want her. It's okay to --
"Fuck me!"
Fuck. Shari put her hands on Tim's hips and pulled herself inward. The jackal yelped.
"Shit. Was I too rough, girl?"
"N-no! Well, maybe, b-but it feels good now! Please... go deeper!"
"R-right..."
She began to thrust slowly, letting their juices lube them. And God it did feel wonderful, that tightness squeezing around his length, Tim's moans and whimpers encouraging him to push deeper, faster. But still she held back, afraid of succumbing again to that rush of lust.
She could feel it building. It made her frustrated, holding it back. Then... she saw Tim groping at her boobs again. I want to do that! With a possessive growl, he bent forward, pushing the jackaless into the bed, his hand reaching around to dig its claws lightly into yielding mammary flesh.
And it clicked. This feeling, this power welling from her balls and her throbbing heart, wasn't a threat. This power was his. Was him. Tim writhed delightfully as the dam broke and Shari began to pump like he meant it.
"Ohh -- ohh -- Shaaa-hariii..."
"Feel it, girl?" He growled. "I am -- gonna fuck you -- ah -- like a bitch -- ah -- in heat!"
"Oh!" Despite her awkward position, this declaration made Tim try to push back, instincts eager for consummation. And with both of them pushing, Shari did manage to pop her knot inside, bringing them both to climax, releasing the lust that had been building since they first smelled each other in gouts of white-hot seed, flowing femcum and spasming muscles.
"Hehh...ehhhhh..." Shari sighed in satisfaction as his body relaxed, undreamed-of warmth spreading through him. He let himself rest atop his mate, enjoying the warmth of her body beneath him and around his maleness, the heat of their mingled cum held in by his knot.
"Oh girl..." He didn't know how to express the satisfaction he felt -- at his performance, at her performance; at being the first to put his seed in her womb. So he just squeezed her breast.
"Ohhh Shari..." Tim's moan trailed into a tired giggle. "Still mind being a boy?"
"No."
"Good, because you've made me love being a woman. I wonder if I'm pregnant."
Shari's belly flipped. Part of her was suddenly frightened that she'd been a "typical" thoughtless male, part of him was excited at the prospect. But he shushed both sides.
"I'm pretty sure we can't, or I would have asked for a condom. Culpeos and Ethiopian jackals are two different genera. We shouldn't be able to hybridise."
"Booo." Tim turned her head onto its side, glaring up at Shari with one reproachful eye. "Don't you want to have puppies with me?"
"Cubs."
"Whatever, nerd." She stuck her tongue out. Shari nipped at her neck, and Tim giggled.
"Are you serious, though? Because species aside, I would hope that transformations that only last for five days wouldn't result in pregnancy."
"Yeah. I suppose you're right. But that doesn't answer my question. If we could make babies, wouldn't you want to?"
Shari thought about it for a while. Then he licked her. "Yes. You sexy jackaless. I think you'd make a wonderful mother for my kits."
"Yay! ...Um I seem to be stuck to your dick..."
Shari laughed at the jackal's futile efforts to pull off. "I don't suppose you've ever heard of a knot?"
"Not on a dick!"
"It's a feature of canine penises. You remember those two bulbs at the base of my dick you were licking?"
"Yeah."
"They swell up -- and your pussy lips swell up -- when I ejaculate, locking us together so my seed has plenty of opportunity to fertilise your womb."
"Oh." Tim sounded rather wistful. Shari licked her again.
"Maybe we can ask Dr. Harrison about making us fertile. I... I don't think I want to go back to being a girl. Or human."
"Yeah. Me neither."
"Meanwhile, let's get more comfortable."
Working together, the two canids got onto the bed. Shari managed to snag his phone, and he read off facts about Ethiopian jackals -- and canines in general, such as how in the wild they would stand butt-to-butt while knotted to fend off predators. Or how they could cum multiple times while knotted -- a fact he was happy to demonstrate.
Eventually his knot deflated, and they began answering some of the questions in the packet. Shari took notes, since he had forgotten to bring his. Soon, however, they began to explore their bodies again, and it wasn't long before they were knotted again.
"Does this..." Tim yawned. Right in Shari's face, but he didn't mind; admiring her limber tongue as it curled amidst her sharp little rodent-killers. "Does this make us mates?"
"Yes." Shari licked her nose. "I believe it does." He added mischievously, "You don't mind if I spend the night, do you?"
"Sly fox. I can't very well say 'no' when I'm stuck to you." They both laughed. "Nah, my parents won't mind. They've been hinting for a while that I needed a girlfriend. The fact that I AM the girlfriend won't bother them, as long as I'm happy."
"I'm glad I made you happy... sweetheart." The endearment felt a little strange on Shari's tongue, but he'd always liked that one. He nuzzled along her snout, and began groomed her forehead. She giggled.
"'Sweetheart.' I'll have to think of something... to call you..." She tucked her nose against his neck, and slowly drifted to sleep.
Shari lay awake for a while, relishing his afterglow and the feel of all those breasts against his body, swelling and retreating with Tim's breaths. He mulled over his transformation, how it felt to be a boy. No, a man. A culpeo... todd, he guessed he could call himself, genetics be damned.
Yes. He flexed his groin, feeling his cock tug against Tim's embrace. This is good.