Should I be worried?

So I've been dating this guy for almost a year and he has always been honest with me but the other night he got really pissed at me and so this morning I did what I have never ever done before and looked through his phone, I hate myself for doing that and I don't plan on doing it again, but I found out that he has been looking through the craigslist platonic section. He hasn't responded to any of the posts or anything but the fact that he's looking kind of scares me because I really love this guy and when I asked him about it he straight out said he looks through them but he isn't going to cheat on me or anything he just looks out of boredom. Since he has never lied to me I want to believe him but a part of me is unsure. Should I be worried and what should I do? I need advice.

It sounds kinda fishy. I dunno if I buy the boredom excuse that he gave, but I do know that people can do strange things simply because they have nothing else to do. I think you should just wait it out. You can be worried about what he is doing (it is normal to worry because you are just concerned about what is going on), but don't make a big deal about it unless you find out something in the future that indicates that he is being unfaithful.

I just wanted to add that even though you may worry a little bit, focus on the good parts of your life and relationship so that you don't worry too much.

Thank you for the advice. I do try to focus on the good and there is a lot of it, because of him I have become more outgoing and I've learned so much and he gave me his class ring from when he was in his school and has me wear it on my ring finger to show that I'm his and I like that but then he says something and it just makes my mind goes straight back to thinking about the bad. When I asked if he realized that him goin through that stuff does hurt me he got upset but then I guess to make me feel better he put this "latitude" thing on both our phones so if we wanted we could track eachother when we're not around eachother. I haven't looked at it once, it kinda makes me feel like a stalker havin that but I like the fact that he's tryin to make me feel better.