I have one rule of thumb. If your partner cheats on you once, chances are it is going to happen again. My point of view is that a relationship is based on trust. It happened to me once, but never again. It is very difficult to trust again once someone has broken the chain. Remember, we must never break the chain! It is stated in the bible, to never tire of loyalty. Faithfulness in a relationship is the most sacred part of love. If he is not loyal, then there is a problem.