Is NOBODY wrong in the post ? POST : My boyfriend and I began seeing eachother in the summer. I asserted to him that he was 'just sex' - I didn't want a relationship and would never be anything more. I would only be living in his city for two weeks, too, and made it clear I had no intention of seeing him after that. 

Except I did and I made the six hour drive to see him and spend a week with him about once a month for the next three months. 

We'd made it clear that we were one at a time people - essentially exclusively fucking. I told him that if he were to develop an interest in anybody else, to tell me and break it off.

We finally admitted it was probably a bit more than sex and we began dating about four/five months in in September/october, and we love eachother despite the difference.

However, I recently discovered that during the summer, while I was driving up to see him, he took another girl home after a party and she spent the night. She left hours before I arrived. They didn't have sex in the end but he admits that that was his intention. This was at the end of July.

He didn't tell me this, despite me asking throughout our relationship if there had been anybody else. He deleted the messages with this girl before I could ever read them but he swears he only sent her one and then ghosted her. 

Granted, we weren't together. And I was adamant that he was just a shag at the time which probably didn't make him feel too good about himself. But I was driving the six hour journey to see him...

When this came out I also discovered he used to have a sexual relationship with a close friend of his, despite assuring me he had never slept with any of his friends (I have - and he knows exactly who it was and what went down). He assures me nothing has happened with her in the time he's known me, despite keeping this from me. It turns out they've met up a few times, alone and with other friends. Again, he's deleted the messages with this girl so I have no evidence of anything happening but I'm suspicious because the messages have been deleted and he lied about who she was to him.

I am incredibly insecure about all this and have lost a lot of trust in him. It generates many arguments between us. He thinks I should believe there's nothing more than he's told me, and draw a line under it all and live happy ever after. AITA for being unable to do this?