Snooped on bf found bad stuff?

if it is just one occurrence... I would say let it go. what I would do is check up on him every once in a while, and then if you see a pattern that is continuing you know what to do. but if u tell him that u were snooping then he will hide things better. play your cards close to your chest and give him the benefit of the doubt, but if he is acting funny you can check things out. sorry 2 sound cynical but ive been burned one too many times...