Women are fantastic detectives and if we are looking for it, guaranteed we will find it! By snooping we're either making our insecurities his priority, or attempting force of a wandering man into commitment. Either option ends in mistrust. But if we even have to do all of that, we already don't trust the man. What good will finding dirt do for us anyway? Prove our suspicions!?! If we even have the suspicions, we're already at a loss. Anything "found" from that point forward becomes irrelevant.
There is not a whole lot that needs to be said on this topic. You either trust the man or you do not. If he gives you a reason, you have a choice. If you forgive him, be mindful of your insecurities. If you bring up those insecurities later, the shame is no longer on him.