Texting

My boyfriend and I have been together for almost 3 years. We have a 7 month old together and a6 year old that was from a previous relationship but he treats her like his own. When we first started dating,one of his friends sends me a screenshot of him texting other girls,telling them they're beautiful,sexy and everything. He at first lied about it but when I threatened to have his friend over to confront him he told the truth. He apologized,said he'd never do it again and even threw his phone in the pond. So I forgave him. I've had some major trust issues not only because of that but every relationship I've had I've been cheated on. It makes me feel like I'm not good enough. Well now I found out he saw a girl at the mall he went to school with. He been messaging her on Facebook,said she was sexy,that her ass was so nice and filled out great and that he loved how she looked. He then asked to meet up with her to go out to dinner but she never replied. I also found out he has a profile on dating website called plenty of fish. He's also been looking at porn,which he originally told me that since he had me that he didn't need it so we had an agreement that he wouldn't watch it (I hate it so there wasn't any need for me to agree on it). When I confronted him about her he said that shew meant nothing to him and that she lived to far away for him to do anything with her. I'm like wtf?! Why does distance matter? I personally feel that if you're doing all of this then you're trying to find somebody else. Opinions?