There is no room for politeness on stage. It has the word 'lie' in it.
While technically not true when spelled out, there is ‘lie’ in ‘polite’. Also, it’s not a coincidence that ‘politeness’ has the same stem as ‘politics’. We want truth on stage, not lies. We want story on stage, not endless discussions.
As improvisers, we are trained to make our partners look good. But sometimes it seems we’re mistaking this with making our partner’s characters look good, and that gives us the exact opposite result!
Stick to your point of view and don’t give in too soon. Your partner doesn’t want you to steal his or her point of view. Similarly, never sigh on stage, it’s a show of defeat and compromise. Compromises make everyone look bad.
Don’t let your good manners from the real world interfere with your scene work. They really get you nowhere on stage. :-)