Only my close friends or people that know me good is cool as long as they don't get nasty. I think is common everywhere in the world.
because you feel conferable and close enough to do It.

yes. but in a nice way...
uh.... playing the slug bug game is fun... (sounds childish but whatever)...

as long as it is good natured and i get to tease them back lol

Only some of my really good friends can
get away with that.

Anyone else, they're just asking for trouble.

I believe it's about the same in both countries.

Yes, I love it! I think it is common where you get people from Irish backgounds....Liverpool in the UK is where I'm from and we're pretty much all Irish. We love the craic! It is partly a cultural thing, taking the piss, definitely.