Jennifer was writhing on the floor from her brother messing with her pussy; tongue sticking out from climaxing. Mike was surprised when he took his hand out. Feeling his slick fingers, he spread around the liquid on them. He couldn't help but be curious and gave them a smell, finding that it was rather sweet. Jen's pheromones from her pussy seemed to be working on him, as he licked his fingers clean of the juices. He had no idea why, but something awoke in him instinctively, blood rushing south to make his pants tent.
Jen barely regained enough composure to lift her head, just in time to see her brother plunge his dick right into her defenseless pussy. Jennifer teared up from the incestuous penetration, seeing her brother ferociously pound her detached cunt. "T-transform or dare..." She murmured, feeling her mind go crazy from the pleasure. Her brother couldn't hear her, too busy fucking her pussy and sucking her nipples, so he would end up with both. "For your t-transform..." Jennifer couldn't properly get the words out, with the trauma and pleasure messing up her thought process. She tried to say "I hate that my body fell to pieces, should be able to recombine it." but she only uttered "my body fell to pieces...able to recombine it..."
Mike's tip banged against the entrance to Jennifer's womb, and she would hate to have him cum inside it. SO she quickly aimed to stop him with a dare, "For your dare...." But Mike finally unleashed his virile brotherly cum into Jennifer's uterus, filling her up quite a bit. The flux of warmth made Jennifer arch her back, worried that she might be pregnant from this. "I don't want my brother to be sexually attracted to me; it's not good. Only other people should want me!" She tries to spout, but getting choked up she mutters, "want my brother to be sexually attracted to me....not...other people..." And with that, the curse goes into effect; Jennifer's feet come off at the ankles, with her legs separating at the knees and upper thighs. Her pussyless waist separates from her torso, as her hers and arms detach from her. Her torso falls in half, with her head coming off of her neck. Her head splits right under her nose, with the bottom half having her mouth, as she ends up fainting from the incest and the collapsing of her body.
The thud of her body on the floor makes Mike finally look up, finding Jennifer in pieces. Although, since she is unconscious, he doesn't think it's actually her. "Cool, a weird doll that looks like my sis." He says, stepping over to her. It was then the dare took effect, as he finds himself super hard staring at Jennifer. Shrugging his head, Mike begins to reassemble Jennifer's body, putting it nearly completely together without her head on top. Instead, he places just the bottom half of her head on her neck, creating a sexy looking doll. Groping her tits and fingering her pussy, he carries her over to his room, locking the door and placing her on his bed. Leaving the top half of her head on his shelf, Mike licks her feet as he sticks his dick back into her pussy.
He spends the remainder of the morning fucking Jennifer's body and cumming inside her, unaware it was actually his sister. It's unlikely he would mind if it was actually her now, thanks to the misspoken dare, but he crashed his hips against hers fiercely. Violating her body without a second thought, he fucked her all morning.