<human>: (B/S) I met my boyfriend through work. At the time we both were in relationships with other people. Attraction to each other grew extremely quickly, and we began confinding in each other regarding the problems in each of our relationships. As time passed, feelings grew for each other and he ended his relationship with his girlfriend at the time. I was a little hesitant of breaking up with my boyfriend, as I had chased him for a long time previous to us getting together but instantly felt like it was something I didn't work.

So feelings grew and eventually I ended the relationship with my current boyfriend. Things moved quickly and within a couple of weeks we were a couple. Everything seemed great.
He stayed over mine most nights and it seemed perfect. Then his ex added him on Facebook.

A horrible feeling hit my stomach and I had it out with him. After lying several times I read the messages after he gave me his phone (he didn't want to.) I found mmessages with him claiming he still had feelings for her and that he wasn't over her. After having a massive argument, both of us crying he agreed to have no more contact with her.

Things went back to normal between us, and it seemed fine. He dumped me out the blue on Christmas eve.
I was devestated. All contact was stopped and I was finding it hard to cope without him. After several weeks of no contact, he gets back in touch. Begging for forgiveness and realising his mistake. We have been "dating" again for the past couple of weeks and everything is ten times better than it was before.

But now? I have this horrible fear of him cheating. Even when he's left alone with my best friend, I have a horrible feeling they are in bed together (I've known her for a couple of years we are house mates and she hasn't done anything to betray my trust.)

Any advice would be great! Thanks in advance.

Can you give me the gist of the text in a nutshell?
<bot>: Met boyfriend through work. Dumped me for his ex. Got back with me. I have a fear of him cheating.