Trying to,

I always thought that my ex had told me everything... then after the break up I realised that he had told me very little... To prove to me he was faithful when we were actually together he provided me with bank statements, phones bills etc.. but no matter thow much 'proof' he gave me, now when I look back there are many unanswered questions about when his relationship started with his new woman.. I will always doubt him for that and it hurts to think of being lied too by someone who holds your trust.
I don't have answers to what you want - it's up to you if you want to snoop and see what happens - but if he is hiding something from you would you leave? and if not then what is the point of finding out?