The door swings open, since John forgot to lock it in his eagerness to jerk off, and his older sister Jennifer steps in. She's the most naturally attractive sibling of the three, having been a popular cheerleader before getting serious about studying and her career. As she stands in John's doorway, her dark blonde hair is pulled into a tight ponytail and she's wearing a very professional gray suit over a white top. She has nice curves, D-cup breasts and a nice ass, but she covers that up with her serious work clothes. She looks tired, having just got off work.
"Hey John, I've got pizza downstairs and... WHAT THE FUCK? It's bad enough your sister's in the other room playing with some goofy toy, but now I catch you in here jerking yourself off?" Jennifer sees her brother, splayed out on his bed with his fingers around his small dick, his lower half glistening from cum, and his mouth hanging open in post-orgasm bliss.
Jennifer moves to cover her eyes, but then stops.
"John? Is that you?" She asks, noticing the small pair of breasts on her brothers chest, his soft and feminine facial features, and his long hair.
John opens his eyes and smiles when he sees his sister, but then the shock of getting caught catches up with him and he rolls over to cover his still-hard (but still-small) dick. He whimpers something in his newly softened voice.
Jennifer politely looks away, figuring she has just learned something new about her brother. He must be wearing a wig and makeup... and those breasts must be some kind of silicone form.
"Listen, I... I guess you're going through something and..."
Jennifer's eyes land on John's phone, which fell near the door when he dropped it. While cumming, he must've clicked on the next video, which is still playing. It's called "Lesbian step-sisters share a cock" and it involves three young women taking turns slobbering over a dildo. It's one of those phony POV videos where you're supposed to pretend it's a real dick but it's clearly not. Either way, Jennifer had never seen anything like that and, much like her brother, is a little curious.
She casually slides John's phone into her pocket and heads for the door, closing it behind her after saying "Oh, uh, pizza's downstairs..."