Considering the word in question is pretty much all over TV I would say that they have likely heard it before unless they lead a sheltered life. I'm not sure that it is good to be using it, but I do not think it is too bad. Of course "we just kicked their f'n asses" would certainly be over the line.

(disclaimer) I do not have kids, so this would be the opinon of one that does not have to deal with the repercussions of saying it

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