What I remember is that Kurt and Blaine are dating, and Kurt is either a Skank or skank/badboy-esque.
Blaine has a bp and is terrified of Kurt finding out and dumping him. Then one day he's changing in the locker room and Kurt walks in and accidentally sees him naked. Blaine freaks and runs out and avoids Kurt for a few days because he's sure that Kurt is going to break up with him. Then Kurt shows up at Blaine's house wondering why Blaine's been avoiding him, and when he figures out that it's because of Blaine's bp, he assures him that that is definitely not the case. Pretty sure they proceed to have sex for the first time.
Ring any bells? Please and thank you!
FOUND by Anonymous: Untitled prompt fic by endofadream