Alex has grown tired of watching her new stepsister get whatever she wants and is embarrassed to be associated with her babyish behavior, especially when Christy has tantrums in public to get what she wants! Alex reminds Christy that she's the older sister, even if just by one year. If no one is going to teach Christy how to act, Alex will have to. She pulls Christy over her lap and begins to punish her the way that she would have been if she acted this way: with a bare bottom spanking, over her knee.
Alex tells Christy that she's her baby sister now: she certainly acts like a baby, after all. To prove her point, after a hard spanking that leaves Christy's bottom bright red, she tells her to lie down on the couch. Alex tells Christy that she's going to teach her a lesson in humility and pulls out a diaper, baby wipes, powder, lotion and a pacifier.
Christy is overcome with embarrassment and immediately loses her sassy attitude. Christy hides her face in shame as Alex spreads her legs and baby wipes her pussy, then makes her hold an exposed position for lotion and powder. She's then diapered up while Alex reminds her that she's nothing but a naughty little baby.
Christy's final humiliation comes when Alex makes her play with some baby toys and suck on a pacifier...while she takes photos. If Christy doesn't start behaving herself, Alex is going to show these to everyone at school!
Although Christy Cutie has fantasized about diapers for quite a while, this was her first time wearing one as an adult...at all, let alone on camera! She was very embarrassed, but when Christy's princess parts are on display it's pretty obvious how she felt about it! Alex and Christy are best friends in real life, so it was really special for them to explore this kind of play together!