When do you decide that the B.S. of dealing with someone/a crowd is not worth the effort anymore? How low or how high is your tolerance?

With a person - when their words say one thing and their actions another. When they keep me in a loop of guessing what's going on, when they're 'unavailable' all the time.
With a crowd - I generally don't deal with those. Or cliques for that matter. They all seem cultish to me.