I`m sorry about your situation. My limit is...3-strikes, you`re out (Mets fan
). I wish you luck.
Edit: Just so it doesn`t sound arbitrary or douchey...the reason for my limit is this --- the first time around, I will communicate to whomever it is that I feel what they did is wrong and why. The second time around, I will tell them that the next time that happens it will put an end to our relationship. And, the third time, I will break off contact.
But, when it comes to cheating...the house would probably come crashing down the first time around. And, the reason for that is because I have put a tremendous
amount of work into not being a cheater. I think a lot of the behavior from people around me encourage cheating (women are typically interested in me most when I have a partner, partners who will "test" me by being bitchy, people who are non-monogamous in practice yet will never agree to consensual non-monogamy, etc.), yet I made the conscious decision not to. I have been lonely, I have let people I had strong feelings for go, because I did not want to be a cheater.
So...everyone who`s in a relationship with me will know how much of a deal-breaker it is from the bat. To use another baseball jargon.