Struggling to trust

[Scabiosa]

The first time I met my current partner was 5 years ago on a night out. We had such a connection, shared the same sense of humour blah blah. He walked me home, we exchanged numbers and he kissed me goodnight.

I was so excited about him. The next morning I messaged him to say what a nice time I’d had and hoped we could meet again. He responded by saying that he’d love to but very casually said he had a wife and baby but this wasn’t a problem for him. I was staggered and disappointed, he hadn’t mentioned this at all the night before. He told me he had- but I know he definitely didn’t. As he was pursuing me I assumed he was single. Silly me. Anyway, I called him a few choice words and declined his clandestine offer.
Fast forward two years he contacted me again out of the blue. He’d left his wife and was living alone. He’d always thought about me, we wanted to approach me again in the right way. I agreed after a time and we started dating.
Everything went relatively smoothly and we moved in together however very shortly after moving in I found out that in-fact he’d left his wife for a colleague but it hadn’t worked out.
I was very upset by this- as I was very wary about giving it a go with him after the way he behaved when we first met so he’d promised he’d always be completely honest with me- would never treat me that way. Blah blah blah.
Anyway. He was still working with this colleague so my paranoia got the better of me and I went through his phone. They were still in contact- he asking her to come in to the office ‘xxx’. Sending her pictures of landmarks on days out WE’D been on. I was devastated by this. I felt like he’d completely misrepresented his situation AGAIN: I eventually confronted him and he apologised, said it means nothing- just friendly but I can’t really get passed it. I don’t feel like I can trust him, I’ve really tried to relax and let it go but I can feel it simmering away in my chest. I feel like I’ve been tricked.
I struggle to express how I feel because I often doubt if I’m entitled to feel the way I do. I would appreciate some perspective if anyone has a moment

He's a faithless, lying cheat. You are struggling to trust him because he is untrustworthy.

I don't really think you have many options other than to end this. Is this really the relationship you imagined yourself to be in when you were growing up?

You feel like you have been tricked because you have been. He has lied to you from day one.

Dump him. You're struggling to trust because he has proven himself untrustworthy. He was cheating on his wife, and he's at the very least keeping another woman as an option while being with you. You weren't so special that you turned his head in his marriage - any woman would have done, and did. And he contacted you because he was at a loose end and going through his mental black book, not because you were so amazing. It was just a line. He's just a bog-standard liar and cheat. You can do so much better.