“Oh god, these really are annoying...” said Martin, struggling to squeeze his huge tits into his sister’s too-small bra, already overflowing the already generous cups. “...They’re so big and they won’t fit into anything! And they’re so big and wobbly, they nearly throw me off balance with every step! My back aches, and the boys at school won’t make eye contact with me anymore... even Dad’s catching glances at my - I mean, your - chest! Can’t you swap us back yet? Please?”

Jessica laughed, not taking her eyes off the comic book she was reading. “I told you they sucked, but you didn’t listen. Not such a ‘blessing’ now are they? I think you’ve still got some learning to do.”

As Martin groaned and continued to try and hide his impressively deep cleavage, his nipples still poking out, Jessica checked that her wand was still in her pocket. A couple days prior her older brother Martin had been poking fun of her enormous chest. Jessica had been an early bloomer and easily had the biggest breasts in school, but she hated the inconvenience and attention they brought. Her brother making fun of her and saying that it must be great having giant titties was the last straw - using their dead mother’s wand, she swapped their bodies so he could feel what it was like to carry around those boulders all day. After a while, Jessica realized she loved the freedom of being a guy, so she plotted to make the swap permanent. According to her mother’s spellbook the only way to do this was to get her brother to have sex in his new body - but knowing Martin would be reluctant to violate his new body, she had been mixing a permanent libido-enhancing potion into his drinks. She had no idea how strong it was, but she didn’t care if her old body became the school slut. That was Martin’s problem now.

Suddenly Martin’s attitude changed. He crossed his legs as something wet began dripping from his legs. “Uhhh... I gotta go...” Watching her brother head upstairs, she continued reading until she heard the sound of female moaning upstairs. She didn’t remember any guys entering the house to meet up with her brother, so she went to investigate. Opening the door to her parent’s room instead she found their father balls-deep in his own daughter’s pussy, giant breasts slapping against Martin’s own stomach with every thrust.

Seeing his sister in the doorway Martin called out in horror, still continuing to fuck his dad. “No! It’s not what it looks like! I’m just sooooooo horny!” he cried as he came his first female orgasm, not long before his pussy filled with his own father’s seed.

As Jennifer closed the door, letting them return to their taboo sex, she realized she had an erection stirring in her own pants. Taking a moment to consider what she was about to do, she opened the door again. “Mind if I join in?”