Search Results: signs of cheating boyfriend

I have been with my boyfriend for two and a half years now, he is my first serious boyfriend although I have dated others. I am his first girlfriend and obviously serious girlfriend because he never had the attention... so it is obvious that if he gets attention from a girl he loves it and cannot pull himself away.
Since we've been together I check his phone and laptop regularly, weather it's wrong or not I've been cheated on in every relationship I've been in so I have trust issues.
Now about 6 months ago he signed up to a dating website based on just screwing around with people but never actually messaged anyone. I forgave him for that, but, last night on his phone he had two Internet pages up both about hooking up with people. He says they are pop ups so I went onto his settings to check if the pop ups had been blocked. What do you know they are blocked.

This isn't all he does, he messages girls trying to get attention, I don't know what to do. He says he loves me and that I'm gorgeous, he tells me he'll never hurt me. So why does he?
Do guys just crave the attention from other women besides their partners? What should I do? Should I just leave..

I`m kind of torn here see my boyfriend went on a trip to Seattle and I ran into some of his friends who I guess as they put it find me beautiful and claim they love me its only three of his friends and he has a lot that I`ve met when I ran into them they wanted to buy me a drink and kept saying things like your beautiful I love you now I just told them I am with your friend and I don't cheat and now he has one friend who's actually the reason we met again since I`d met my boyfriend through a friend of mine he drove me home one time and I thought he was cute I just was to shy to ask him for his number but when I went to hang out with another friend of mine only a couple weeks later he was with him and this time I asked for his number as I took this as a sort of sign that I should this friend of his said that my boyfriend is his best friend so we can't do anything at least he thinks that way the others seemed to understand as well I think but its happened a couple times now my boyfriend introduce me as his girlfriend to them all so I thought they wouldn't even think of it I just don't want to be the bad girlfriend who says it to my boyfriend and have anything happen with his friends and him but I don't want this to always happen I`m ok with making nice and being friendly to his friends but not cheat on my boyfriend as I know what its like since my ex cheated on me with my best friend so I would never wish the pain of that or similar on anyone else what should I do?