Suspicious Girlfriend.

My boyfriend has been acting a little funny lately, so I peeked into his message inbox to just to see.. and he has been talking to a girl who has the same birthday as me. Also he's been talking to a female he had relations with years ago, but never went all the way with. I feel he still longs for this other girl, but I don't know.
An hour after this, he changed his password, but its impossible he could have known I was even in his account.
How should I confront him about the first one without getting him p/o'ed about me being snoopy in the first place? How did he know I was in his fb account?
Other than this we had an almost pristine relationship, so I'm worried.

Honesty is the best policy. It's not healthy to have this much unspoken within a relationship, you'll both be itching to say (or avoid) what needs to be said.

Don't make accusations, just explain why you're upset and ask to talk it through. If he flies of the handle, it could be a sign that he's not mature enough to handle a relationship. If there's nothing in it then he should be happy to sort things out - he'll want you to be happy if he loves you. If not, sod 'im, you can do better!!!

Trust issues are difficult to work through, but if you bury your head in the sand now, it could lead to trouble later on. Do you think that this niggling feeling of betrayal will naturally go away with time? Or will you never let it go till you get an answer?

Stay strong and do what's right for you. Good luck and I hope you get what you need to feel happy and secure again x

He can look at the history on the machine and see where it's been on the Internet. Just click on Favorites then the History button and you'll see it.

If you know the girl's birthday you must have read the text of the messages. If they read like he was trying to hook up with them you may have a problem but if he's just communicating with them, that goes on all day on FB,

Asking how you can discuss information you got from snooping through his personal stuff without offending him is asking for magic. The first evidence of someone cheating is missing time. Without more evidence than what you've written, I'd forget it.