Trust / managing emotions / lying by omission?

Thank you in advance for reading this. I have few places to turn to for advice at present, so I'm writing this in the hope that someone could offer some objective advice, as my objectivity and pragmatism are sadly lacking at the mo. I'm currently in a serious relationship that has been ongoing for just over a year. My boyfriend is in the process of moving in with me. I have been married twice, with both partners eventually cheating on me. This has left a deep mark. My other half is still married and when I met him, he wasn't entirely over his wife. He has made her, for me, a woman I feel in competition with as "she is and was the love of his life" and "she is remarkable". Unfortunately, whenever I now bring her up, he gets incredibly prickly and irritated and has said that "the divorce will happen when it happens". I find this incredibly disrespectful towards me and my feelings and our current relationship status. We have agreed that when he formally moves in, a formal contract and rent book will be drawn up and used in order to protect myself. I now find myself continually looking for any indication that my boyfriend might be cheating. And it appears that something could, potentially, happen. He has made friends with a new female colleague at work and has been giving her lifts to work and back and has refrained from telling me this. Why? For me, he's breeding dishonesty. If he'd told me, I probably wouldn't have batted an eyelid. They were out together last Friday night on their first works do. (He is new there too). She messages him during the day and on an evening and no, he doesn't always respond. His behaviour seems sneaky. He is not a man who easily opens up and when I say I need to talk about something, he will try as much as he can, but when I hope to hear "it's ok" or "of course I love you, don't be daft" or comments along those lines, I get nothing, nada. Silence. Can anyone offer advice on how I can improve this situation? I realise I have issues. He is aware of my past experiences (my ex-husband also looked on whilst I was raped and managed to "escape" to leave me to fend for myself) and I have worked very hard on myself to even attempt a relationship with anyone new. Talking doesn't seem to work as he closes off even more, telling me that he doesn't even understand his own emotions. I am feeling very mixed up and not sure where to turn from here. Thank you