I cant ever say the right thing!?

every time im around this guy i always manage to make myself look stupid like today i was walkin down the hall talkin to my friend mindin my own biz and said my *** is sore (from workin out) cuz thats what we were talkin bout and he walked around the corner toward us and heard it and kinda had a shocked look on his face like oh wow, skank. and now i feel stupid! advice? plz and thanksha my lovelys