Should I confront him?

I know snooping is wrong, but my partner and I are completely open with each other. He had picked up the iPad and was looking through my Facebook while I was brushing my teeth, so I picked his phone up and had a little look while I couldn't sleep. I found this convo that is really not sitting well with me. My SO went out to the pub (greeny) on Friday night to celebrate his birthday with some friends. I was working late, then came home with our 4 month old, so didn't go to the pub to celebrate with him. These texts are from that night.

I don't know whether I should confront my my SO or maybe go straight to Suzie, who is the little sister of a friend. But from what I can tell, my SO was checking to make sure Suzie didn't see anything because he knows she could/would tell me. Or maybe I should trust that he's is innocent and nothing happened.

I would feel so shit if I was at home putting his baby to bed while he was letting a drunk girl make a pass at him 😐