>>2193093B. Would have Aria to wear the slingshot bikini to impress Elmira. Elmira might let Aria keep it for later and give back the clothes.
Aria can be naked with the bikini still intact. Elmira can convince Aria to be naked for something, like a better swimwear or clothes (better as in more revealing and embarrassing) and the tennis clothes.
No need to break something to be used or traded. It would also be interesting if the slingshot was traded for something better than a slingshot bikini. But I can't imagine what that is though.