My boyfriend is so sneaky, what do you think?

Ok, I know this is the last place to talk about this but I am just looking to see if I am crazy. So, I have been with my boyfriend for over 3 years and we live together. He left his e-mail inbox open and I found all of these "Adult Friend" sites he registers with. I also saw that he responded to personals on Craigslist telling these random females to check out his myspace and text him. Then, I saw that he recently paid to see live girls or whatever on webcam. This isn't the first time something like this has happened, so I am really frustrated. More disappointed than hurt. I mean, this stuff is incredibly stupid-the sneakiness and all that. What do you guys think of this? We have a great relationship but I don't know. I see it as 'if he hasn't cheated on me yet, this looks like it will'.