If you're among friends, you can express yourself as you want and don't give a monkey's what others think :) In this case it only depends on how you state yourself and how you want to be treated by your friends. On the other hand, if you try to communicate to strangers, you shouldn't use an offensive language. Otherwise they just won't speak with you.

In Russia's big cities there is an implicit rule that people don't speak to strangers on a street.  So, you can't just walk up to someone and start speaking to them and waiting that they would reply to you in a friendly way. I mean, you can ask for an unknown steet or how to get somewhere, but not more. It's different with girls, you know, you could come up to a girl and start to communicate with her. It's OK. So, actually you don't have a lot of opportunities to swear :)