What bad influence?

Today one boy, someone who's had behavior problems ever since I first met him in 2nd grade, said something in class to me, I don't know why -- he gave that line some use when imitating an Asian prostitute, an offer for oral sex. I told him I would send him directly to the principal's office if I heard him say it again. Should I have just sent him there anyways? Last week when I was in a different classroom, I saw that one of the 3rd graders had been given a citation for saying aloud that he should get oral sex (not in those words, but "--- my private" -- I don't know if he really said his private or if that was edited by the woman on lunch duty. So where are children picking this stuff up? From the TV and movies? Other children? When I was in elementary school, no one talked about oral sex, though they might talk about sex and body parts. Have things gotten that much worse in 25 years?