A is the younger sister (12-14). B is the older sister. (15-17, with at least a couple years between them). They've always been incredibly close, but now that A is entering puberty, it's starting to get pretty inappropriate. B likes to affectionately bully A, throwing her around, playwrestling with her, tickling her... and then the less normal-sisterly stuff, like lifting up her shirt without warning (to help monitor boob growth! Helpfully!), casually walking in while she's showering, and so on. A gets increasingly frustrated by this, and might or might not understand exactly why. Either way, B is happy to offer an outlet.

Size/strength difference is a big one in this, and also the experience gap, with B probably having had a few girlfriends already.

I'm mostly looking to play A, but could be persuaded to play B as well. Good with canon characters or OCs with drawn PBs.