With all due respect, don't stick your nose unasked in other people's business.

Behavior like that makes me far more angry than rude comments.

"naughty words" are not synonymous with "rudeness". You can easily convey a message of contempt for the recipient with flowery, polite words, just as you can easily convey a message of fraternal love with rough words.

If someone told me to mind my language over a casual board game, I'd tell them to fuck off. A friendly jibe is just a friendly jibe, regardless of whether it had the word 'shit' in it or not. Words matter, but far less than intent does - and the intent of telling someone to clean up their act in a casual setting is that they're patronising you.