Yeah, there's some swearing at our games, mostly out of character, but also because most of us refer to the characters in 3rd person about 60% of the time.
I actually manged to offend my players with an NPC. The entire party are Elves. Their first encounter with a human had them saving his life and him going into a tirade about how he couldn't believe he was saved "by a bunch of points".
The looks on their faces as they realized it was a slur made me know I had a winner of an NPC they'd love to hate. They were (as players) really worried to leave their forest as they thought they'd be hated wherever they go.
Nope, this guys just a jerk face. They haven't seen him in quite a while, but they are going to need to deal with him again. They wicked don't like him.