I have a considerably low sex drive, so I don't have dirty thoughts all that often. I've never been shy about discussing sex, sexuality, and all other related subjects, though, so such thoughts don't bug me in the least.
Oddly enough, a lot of people tend to assume the opposite of me because of my knowledge and interest in said topics. Apparently you're not allowed to be open and enjoy talking about sex-related topics unless you're some sort of hormonal sexual deviant. xD
Ah, the silly rules society thrusts onto us..