okay but what about Stiles and Brett as fuck buddies?
like an AU where Stiles goes to Devenford Prep and he meets Brett. maybe they butt heads at first which turns into hate sex in the locker room. but then they start hanging out and become friends. they stop having sex after that because they’re friends now and you can’t fuck your friends, right? until Stiles brings up being fuck buddies and Brett is down so they start messing around again. then the 4th of July rolls around and Talia invites Satomi’s pack over for a barbecue and Brett invites Stiles (he figured out Brett was a werewolf early on obvs). Stiles totally had planned on sneaking off and messing around with Brett but he meets Derek and instead spends the whole time flirting with him. (Derek is wary at first because he can smell Brett all over Stiles but Stiles assures him that they’re just friends who like to fuck sometimes.) when Stiles and Derek start dating Stiles and Brett stop having sex but they’re still best friends. (Plus Brett meets Mason through Liam.)
or alternatively I also like
Brett starts having feelings for Stiles and he plans on telling him during the fireworks and the Hale barbecue. when he sees Stiles flirting with Derek he thinks of course he would. Derek is hot and he and Stiles are only friends, right? Wrong. Stiles is only flirting with Derek because he doesn’t think Brett has feelings for him like he has feelings for Brett. So he starts dating Derek and actual falls for him but the whole time Brett has been getting more and more distant. Stiles confronts him and Brett confesses his feels and yes Stiles is with Derek and he’s happy but he can’t help but kiss. Because he’s missed Brett. Missed hanging out with him and fucking him. the kiss doesn’t end at just a kiss and they end up having sex. Stiles feels guilty for cheating on Derek and tells him what he did. Derek tells him it’s okay because he could tell that Stiles had feelings for Brett. And Stiles really does like Derek but he’s also had a crush on Brett since forever. that’s when Derek admits that he’s had small crush on Brett too and was why he convinced his mom to throw the barbecue. which leads to Derek x Stiles x Brett being the hottest poly relationship Beacon Hills has ever seen.