There have been a lot of music etiquette threads, mostly relating to rude people at sessions. There is really only one answer. The majority of people who are rude have one of two reasons:

1. They don't realize they are being rude. 2. They are being selfish, and don't care that it is rude.

In both cases, the cure is communication. Tell them.

There is a woman at my work who often comes around listening and butting in on everybody's conversations, and bossing us around when she wants her own way (she has no authority). Most of the time, people just let her, so that she'll go away. But I've started another approach: When she offends, I just say, "Don't be rude". At the very least she leaves me alone for a while, and sometimes she is thoroughly horrified.

The #1 type of rude person is usually embarassed to realize how they've been acting. The #2 type is usually embarassed to have been caught.

You can't change people's behaviour if they don't know it is offensive.

P.