Too much wine, and the truth leaks out

I would like to get your thoughts on a current situation in my relationship. I’ve been living with my partner for 3yrs now. We met just a couple of months of him moving to my city for work purposes. The beginning days we fully disclosed our past relationships. Or at least I did. Fast track a couple months, and I got the opportunity to accompany him on a work trip to him home city. We were invited by one of his friends to a house gathering. There were many people, but an incident occurred in which there was one woman with whom he greeted with an exceptionally long hug. It was more like they were holding each other. He head, nestled on his shoulder. And they were alone in the kitchen while the rest of the party was in a living room area. They were in there for some time. I witnessed this as I was heading to the bathroom. After the party, I asked him if he had feelings for her. He said no. It wasn’t that kind of relationship. She was a work friend who happened to help him through his divorce. I believed him. There wasn’t really any reason not to. But did find it odd that he’d go back to his home city frequently for “business “. He would tell me he got together with his friends ( she was there too) at a pub every time he went back. It bothered me, but I didn’t say anything b/c I didn’t want to appear needy. That was 7yrs ago. Recently, he admitted he had feelings for this woman. So he lied. And I feel betrayed. My head goes to places that it probably shouldn’t. All those trips back ( right up to the beginning of the pandemic) was he with her? Did they sleep together? Does he still have feelings for her? I asked him these questions and he flat out denies it. He claims that by the time he left his city, he had no feelings for her. He was over her. I’m having a hard time believing that his feelings for her just disappeared 2 months before meeting me. I feel those nights in his hotel room he was not alone. I’m trying to work this out logically but my emotions flare. I’ve moved into the guest room b/c it disgusts me to think of even being touched by him. Our 7yrs together has been peppered with hot/cold from him. And I’m left to wonder if those times things were “cold” between us was b/c he was talking to her, or some other woman. What would you do?