He'll treat her right, right on the end of his dick

Calem struggled with himself for all of three seconds before his improved body did the thinking for him, sending him forward with powerful strides. He made no effort to stop his hands as they reached forward, groped Vanessa's butt and held her hips in a firm grip.

"Ric, I told you, not until later. I want to find someone for my brother first," she said, wiggling her ass a little against who she thought was her boyfriend. "Mmm, you want me though. Are you bigger? Just be patient and you can put" she asked as Calem ground his covered crotch into her, letting her feel the exact size of his cock.

"I'm bigger than Richter, huh?" Calem asked, suitably pleased with the sexy timbre his voice had. He was even more pleased with the surprised gasp that came from his sister a moment later as she recognized his voice. She looked backwards as he wrapped one hand around her waist and moved the other to his shorts, pulling his penis out.

"Calem, what are-ooohhhh...." Calem felt his sister's belly twitch and undulate under his hand as he probed at her barely covered crotch with his shaft.

"Are you wet for me, sister? Or for your shitbag of a boyfriend who doesn't know you from the next pair of tits that bounces his way? He doesn't deserve you, doesn't deserve this perfect ass, this trim waist, these beautiful, heaving boobs." Calem trailed his hands over every part of her body as he named them, pulling gasps from Vanessa, particularly when he squeezed her weighty breasts. He could feel her pointed nipples against his palms, showing just how aroused she really was. "Don't worry, I'll show you all the love you deserve," he said, pulling the cloth covering her damp vagina to the side and pushing his hot dick forward.

"I'm...sorry, Calem, I just....get so horny," Vanessa moaned as her brother's member slowly split her open. "I don't....care about them. I just...needed...someone....to fuck me. I'm such...*ahh*...a horny slut." Her breath caught as Calem's enhanced dick reached further into her than any of her previous lovers ever had, continuing for what felt like forever until she was completely full with his meat. Calem nearly came as his hips hit her ass, only barely holding himself back. Still, he couldn't hold back the thick blob of precum that leaked out of his slit, its warmth filling Vanessa as she was infected by it.

Gasping as her lust properly ignited, Vanessa pulled herself completely off of her brother's cock, her body shuddering with desire. Trying as hard as she could to not just impale herself again, she laid down on a towel and spread her legs wide. "Come on big brother, give it to me, please. Give your little sister the fucking she deser-OH FUCK!!" she yelled as Calem pushed back inside, staring her in the eye as his hips jacked into her tight cunt. He watched her write and buck beneath him, her hips pumping to meet his vigorous thrusts, as the virus that drove him spread through Vanessa's body.

Calem watched first hand as his sister's already prodigious tits heaved in her bikini, swelling even larger while she arched her back, making them stand out even more. The sight only drove him onward, somehow increasing the pace at which he fucked her. He stifled her moans with a scorching kiss, their lips and tongues dancing to match their fervor. The pressure on Calem's chest continued to increase as Vanessa's growing boobs did just that, pushing into his own new pectorals. The gasping breaths Vanessa took drove her pebbled nipples into her brother's chest, even through her black bikini.

The added friction was the straw that broke the last of her resistance, finally making her cum. The shuddering grip of her pussy pushed Calem over the edge too, the young man's hips locking against his sister's as he poured incestuous semen into her cunt. Suddenly flooded by fresh, infectious cum, Vanessa's already present slight nymphomania was pushed to the utter limit, her eyes widening with shock and then helpless lust as a need for sex and semen filled her.

"CUM INSIDE ME!!" she howled, thrusting her hips harder to try and get Calem's jizz further inside herself. Her orgasm hit again, then again, and again, each one compounding on the last until Vanessa couldn't do anything other than ride through the bliss. Her muscles clenched and relaxed in waves, unknowingly milking Calem for everything he had stored in his balls, draining him dry. Only when he was sure he was finally depleted did Calem pull out, releasing a wave of cum that Vanessa quickly moved to block, holding it inside her.

"Fuck...yes..." she mumbled, eyes closed in bliss. She slowly opened them and sat up, looking at her brother with features made flawless. "You were right, Calem, you were all I need. Fuck, I feel so good, so full. How about you dump the next load into my cute little mouth? I'd love to see what I taste like on your cock." Calem instantly went hard again, his changed balls working overtime to produce another load so he could do just that. "Look at these big titties you gave me too. Which do you think is bigger, your cock or my boobs?" she asked, looking at him with an inviting gaze.

"Sounds like something we should test," Calem said, stroking his dick to get the cum flowing again. He could literally feel his testicles filling with more cum for his lusty sister. "You should probably get that bikini off first though."

"Whatever gets that cock back inside me fastest," Vanessa said, stripping herself of her swimsuit. Like Calem thought, her boobs barely moved, the firm yet yielding flesh held up by their own supernatural perkiness and creating a sexy valley of cleavage all on their own. Her large pink areolas, the same color as her lips, surrounded her erect nipples, begging to be tweaked and suckled on. Her mouth looked just as inviting, hanging slightly open and allowing Calem to see the moist tongue inside, waiting to be run over his steely length.