My boyfriend and I have been together for almost a year in a long distance relationship. We have both cheated on each other once but this is irrelevant and behind us, since it wasn't a big deal, just a kiss from one of us and several sexual emails from the other. (I was the kiss)

And after the emails he gave me his password to show me that he wouldn't do it again. This was via "facebook" I have been on his account once or twice but only for a joke, to change his status to something humerus. But when going onto the account I was always tempted to look at his emails which I think is just part of being curious. So one time I broke and looked, and only from 2 of the girls he was speaking to, I don't know why, but I was drawn to the conversation. From the girl whom he had "cheated" on me with there were a series of flirtatious emails from when they talk about being on webcam together and her showing him her underwear, which he was pressing her to do, but in a jokey way.

In addition he had a large crush on this girl before we met

The second conversation was with another girl, who tells him she has a crush on him. They also speak of her lying on him at a party.

I know it was wrong of me to look, but these things are bugging me as he would probably be angry if I told him I looked at his account. Which is understandable.

I haven't looked since but it is tearing me apart since I told him about kissing another person but he didn't tell me about the emails, which I found when messing on his computer.

I feel bad fr looking at his account and what do I do to stop being so annoyed about these emails?