James' cock finally deflates. But there's another problem...

They remained like that for some time, Lily rubbing her head against her brother's shoulder lightly while James caressed her stomach with one hand, the other resting on her hip. Neither felt the need to talk, content to just enjoy the warmth of each other. James' knotty dick, meanwhile, kept shrinking , the knot itself the last thing to deflate after who knew how long, neither dog morph able or willing to give a damn about time right now. But when it finally slipped out of his sister, James didn't feel anything seep out of her and down on his crotch. Hadn't he pumped full off... oh boy.

"Mmh, Lily," James began, breathing into her ear, making his sister shiver and giggle, "I came inside again..."

"Who caaares," Lily replied, a dopey smile apparent even in her voice. "It feels so gooood inside me, so warm..."

"But... aren't you worried? You could get pregnant... or... last time, you grew a tail..."

Lily twisted her head to look at James from below.

"Dearest brother, you could fuck me full of puppies and I wouldn't care. I love you, banging you feels amazing, and this tail is just too cute."

As if to emphasize her point, she wagged her tail a little to let it slap against James' thighs, its root wipping over his pointy glans that was just disappearing into his sheath, making the dog morph hiss in pleasure. He returned the favor by lightly scratching his sister's belly with one hand, and soon her right leg was twitching uncontrollably, little yipping noises rising from her throat. James used the time Lily spent helplessly drooling onto his shoulder to think about his own feelings. Lily had always been much more open and foward than him about... anything really.

"I'm... really glad you feel that way," James finally said, throat feeling tight with emotion. "It's just... you were my first, and... I never had a girlfriend, and you're my sister, and... I need time to think, I guess."

"Wow, that's really unfair," Lily panted, twitching weakly on top of James. His heart sank as she said it, and Lily suddenly stiffened. "Uh, no! God, no, I didn't mean it like that! Those belly scritches are, they feel way too good!"

"S-so you're okay with me thinking about this? About us?"

"Of course, silly! I'm not going to **** you into anything just because your dick is out of this world!" James' chest swelled with pride as she praised his cock. "Just promise you won't take too long before you knot me again. Maybe we can do something like step-siblings with benefits?"

James gulped as she said it. Yes, her pussy felt amazing, her whole body in fact, but he was still a little overwhelmed by the quick development. The fact that his prospective mate... girlfriend... whatever Lily would be... was the girl that had been his literal sister for the last ten years wasn't even on his mind. James worred more about that he had no idea how any of this worked beyond the instinct-driven rutting. And then there were the weird changes they were dealing with...

"Mmmh, Jaaaames?" Lily asked in a cutesy singsong. "My stomach feels kind of itchyyyy, could you scratch it a bit moooore?"

Mind still focused on the changes in his life, James began scratching Lily's belly again, her leg soon kicking into the sheets again. That is, until his nails scratched over a slightly raised spot just under her ribs. With a sharp hiss of pain, Lily shot up, forcing the air out of James, and sat down on her haunches next to her brother's legs, looking down her body.

"Ouch, that hurt!" Lily stretched the skin around the painful spot with her fingers and the step-sibling's eyes went wide as they saw what was happening.

"Oh my god, is that a--" James had feared something would happen, and now it came true, right before his eyes. He propped his body up with his elbows to get a better view.

"Nipple?!" Lily sounded very excited at the prospect, frantically running her hands over her torso, and gasped as her fingers found three more similarly sensitive spots in a line under her perky tits. "Ohmygod, I'm getting six boobies, just like you!"

James winced as she reminded him of the decidedly feminine lumps on his front, but his attention was quickly reverted back to his sister as the flesh under her lower nipples began to swell, Lily cooing and giggling all the while. She cupped the budding tits in her palms, evidently enjoying the feeling of the expanding flesh under her hands as she moved them from breast to breast. James felt his cock twitch weakly inside its sheath - Lily fondling her growing tits was undeniably erotic, but after three orgasms in relatively quick succession, he was absolutely spent.

"Oooh, look at them go!" Lily squealed, pulling her lower nipples as if to urge her new breasts to grow faster. "You think they'll get as big as first two?"

"Uh, I dunno," James answered, not quite able to focus in the face of Lily's continuing changes. "Mine are all the same size, so probably yes?"

"That would be so cool! One pair is already nice, but three? I don't even know where to put my hands first!"

"I know, right?! All your nipples want to be played with, and you only have two hands, and--"

"Together, we have four," Lily interrupted him with a seductive smile. "Be a good boy and help me out, please?"

James' ears twitched when she called him a good boy as if to perk up, his mouth opening into a dopey grin. He was a good boy - and he'd show Lily just how good. Sure, he'd just said he needed more time to think about them, but James also remembered how horny his own tits growing in had made him. He'd just be helping his sister out, right? The fact that Lily's swelling tits made his mouth water barely factored in. At all. He dove forwards, grabbing one of the increasingly heavy orbs in each hand and wrapped his lips around the rock hard tip of a third.

"Mmmh, such a gooood booyyy," Lily moaned, caressing her brother's head with her left. Her other hand was presumably occupied with the three tits James was unable to service. His step-sister arched her back, pressing her swelling breast into James' face as he rolled her lower nipples between his fingers, happy gasps his reward. He felt his tail wag rapidly of its own accord, whipping the air behind him, and while James' cock refused to grow erect again so soon, his own nipples more than made up for it, six points of incredible pleasure running down his front. But right now, only Lily's tits were important, no matter how much he wanted to play with his own.

"Oooohffuuuck, keep doing that," James' step-sister gasped, writhing with pleasure as he did everything to drive her wild, sucking forcefully on the throbbing nipple in his mouth. "I'm... I'm so horny... this feels--ah! Way to good..."

The way Lily squealed made James intensify his ministrations. He began flicking his tongue over the nipple in his mouth and pulled on the other two in his hands gently, letting them fall back against Lily's body, and each time they settled down a bit higher. James cupped the swelling orbs on his sister's abdomen, pinching their nipples between two fingers, and pulled his head away from his sister's body until Lily's nipple popped out of his mouth with a lewd sucking sound. The dog morph wasted no time to dive back in, pulling the tip of another, currently free breast into his mouth to slobber all it.

"Nnnnyes! God, your tongue feels so amazing..." Lily panted hotly, clawing into James' hair as her body trembled under his hands and lips. "My tits feel incredible, I think I'll cum... just from my tits--oh god, I'm... AH!"

Lily pulled her brother's head against herself with both arms, burying him in still-expanding titflesh as her whole body quivered and trembled uncontrollably, the overstimulated dog morph gasping loudly all the while. James could barely breathe, but the six soft orbs pressing into his face and neck made up for the lack of oxygen. When Lily's climax finally subsided, she released James from her bountiful bosoms and pulled his face upwards to hers, a dreamy expression on her face. James had a major deer in the headlights moment, barely believing what was happening. His step-sister's lips parted slightly, tongue playing over her teeth, but suddenly, her movements stopped and her brows knit in confusion.

"Wait... what's up with your face?"