it can be very bad. What's you worst experience of this?
Personally, my worst was when there were lots of people round my flat for my friend's birthday. She's a bit older than me, so it was fairly civilised. I believe it was called "drinks" before heading out, which strikes me a being pretty mature.
Anyway, so I was talking to this girl and she was teasing me about how I would die sooner than her because I was a man. I was already quite drunk and responded with "Yeah, well at least I won't get SAGGY TITS."
At which point the whole room went silent, people started looking at me, the girl and her tits, and she looked like she was about to cry. My girlfriend of the time gave me a particularly severe glare from across the room - whether for insulting her freind or bandying other ladies' breasts about in public I never found out. I felt such a fool.