I'll never forget approaching a room where my mother and older brother were talking. I must have been 14 years old, and he, 16. Evidently she was giving him some sexual behaviour advice but the first clear words I head were his, saying, "Well, it's not the face you fuck". I thought, oh shit, he's in trouble now. And I heard her shocked voice say, "Denis!".
Then she said, "Don't you mean you don't look at the mantlepiece while you poke the fire?"
Classic moment, managed superbly :)
Curse words are only words. Most people use them to illustrate a point, out of habit, or just because they are part of the common vernacular. It is easy to teach kids they should not say them in front of certain people. I mean most children can figure out that you can't curse at teachers or most adults for that matter, or especially at older adults, like your parents for example. My daughter has heard cursing all her life and she is now 14 and I let her curse in front of me, but not at me. She can say "That is f'ing stupid" but she can't say "F*** you" to me. Does that make sense? I hope I helped. :)