Here is my opinion. If an A is a deal breaker for you then I agree you have a right to know and you should continue to snoop away. If A is confirmed, immediately set your boundary of not living in an open marriage.
If it is not a deal breaker and you are just going to over look it and hope that it runs it's course. Why put yourself through the agony?
Plus if she knows you know and are over looking it, it makes you look weak.
