All my pj's were in the wash and I didn't have anything to wear so I went into my housemates room to borrow from her (we borrow each others clothes from time to time so that's fine) but while I was looking through her drawer I found my boyfriend's underwear and one of his t shirts.. The underwear was dirty and there was a used condom inside. It might not be him but its highly unlikely its some other guy as I saw both his underwear AND his t shirt (which had his smell in it). My housemate is single also. What should I do? Should I bring it up with her and my bf?