Re: Need help with trust.
there is a BIG difference between checking out a girl and putting up a page on a dating internet site. it does not sound like this guy is taking monogamy very serious, and it sounds like being sexually exclusive does matter to you, so you two have very differnt values there. he may be a very nice guy mostly and have some great attributes, but it does not seem as if he wants to settle down with one person at the moment. i know that is a hard idea to confront, especially when you really want it to work, but he seems to be on a path that does not include being faithful to you.
i am a guy and i would personally bet money that he has already cheated on you. every action you are describing sounds like he is looking for someone else to have sex with. i do not believe that any amount of sitting down and talking things out is going to change where he is at right now. he wants to have his cake and eat it too. so you have to decide if you want to be a piece of cake or not.
ff
ps - no every guy is not like this, do not let his friends tell you such nonsense, there really are guys who value monogamy and being faithful to one woman, i hope you find one.