It's very simple, and it has nothing to do with the word,
there is no PC-ism between friends, friends can say forbidden words and do or say anything they like to one another, no matter how sharp-inhale-of-breath, but strangers may be offended, so err on the side of caution until you know how they feel about such things.
( ..wil, Wed 7 May 2008, 14:38, Reply)