I don't know how I should feel...long post

So last week, a friend couple of ours split up, and she came to hang out and drink. I was up till like 1130. And my fiancee and her stayed up, and watched It chapter 2 cause he knows I don't do scary movies and I had to work. We have a 4 month old who woke me up abut 30 mins after I laid down, then I didn't hear the TV going I peeked out, and the Screensaver was on and I swore I heard kissing. I was stomping around the house couldn't go back to sleep cause I was uncomfortable about them being up together alone. 4 am rolls around he comes to bed and tells me she was asking of I was okay cause I was stomping around being "crazy" and he said I'm making her uncomfortable. Mind you they started the movie at 1140ish. We lay down I slept for an hour get up and ask her if she's riding with me. She says no her bd is starting shit and she doesn't wanna go home to him yet, okay fine so I tell my fiancee. I ask her if anything happened she said he made her uncomfortable but couldn't remember what he said. The day after I ask again, and she's like yeah that night we were talking about our bodies and how they looked a few years back. This girls son is a year old, we knew what she looked like before she had him, she claims she was showing a pic of herself and her boobs came up and he put his finger under her chin and said "thats a beautiful woman" and she told him she was uncomfortable and took her phone back, he claims she was scrolling and it was a bunch of nudes. Then she said the next morning after I already told him, he was taking her home, he came into the spare room and asked if he was taking her she said yes, he talked food and then asked if she liked to cuddle, cause she was with the pillow in the bed and she said yeah I guess. And he said would you cuddle me, she said no. AND he left. But something keeps telling me that isn't all because he changed the pattern on his phone he says because I'm sneaking around looking at it and if I wanna see it to ask him, but when I do he gets all pissed off. A few years ago, he was talking nasty to a girl in our town saying he wanted to make her cum so hard and shit. He denied it until she sent me screenshots and he was like I was just messing around nothing happened I was kidding. And I'm just to my limit with shit. We been together 5 years and have 2 beautiful children and I love him so freaking much but I'm just hurting so damn bad. Idk what to do..