I know that, and in my head I know that even if there was someone else I couldn't do anything about it anyway. It would be on him, not on me. I hate that I do it. I have never found anything. I've been checking his cell phone records for years constantly worrying that he could cheat, even though he has never given me a reason to suspect it.
Well, there is a 180 you can do. If this is a consistant behavior, change it. It's not healthy at all!