You said, "We were born with nothingMy son's concern is the mild curse. He wonders if his teacher will allow them to do the song.
And we sure as hell have nothing now."
I pointed out that they could do it by substituting "heck," thinking, even as I said it, how artistically stupid that would sound. My son immediately said, "If we do that, we might as well just not do the song. That sounds stupid."
This all lead to a discussion of appropriateness as related to audience. My son, though he thought enough to worry about the curse in the song, tested the waters a little by pointing out that Bastille does the song in concert and they play the song on the radio. This lead to further discussion, mostly regarding small children and grandparents at school functions. I think he got the point: in different contexts, the mild can be seriously amplified.
I told him the story of when I used to teach Shakespeare's Othello (the Branagh version, with Fishburn in the lead). In this version, there is a brief scene of nudity, in which Desdemona drops her nightgown on the wedding night. It is brief, so, while showing the film in class (to juniors), I would casually walk by the TV and, with impeccable timing, hold up a manila folder to block out Desdemona's charms for the three second during which they made an appearence. The class, of course, would laugh and jeer and one kid said, "Mr. Mat -- it's not like we never saw stuff like that before." My response was, "Not with me, you haven't."