The FCC has certain guidelines for broadcasting content on the public radio airwaves.
The FCC is sort of the modern version of the puritans. They allow certain "bad" words to played at certain times, but no "bad" words that have to do with sex.
Between the hours of 10pm-6am DJ can play a song that includes the phrase, "Fuck you" or "Fuck Off." But, a DJ is never EVER allowed, regardless of the time, a song that includes the phrase, "I want to Fuck you," or "Let's Fuck."
When I informed my friend Molly of the "Fuck You" vs "I Want to Fuck You" conundrum she deadpanned, "the latter seems much nicer."