Boyfriend is interested in other women

I don’t know how or can’t upload the photo on here but I feel like the way my boyfriend looks at other women is way to friendly even as if he likes them. If a man smiled at me like he does them I would definitely think that they were interested. I don’t know whether to make a big deal of it or not as he seems like he loves me. Another thing that concerns me greatly is that about a month ago he completely changed towards me it was after I found out he had lied to me about messaging his ex to meet up with her (he told me that he watched porn instead) he became cold and horrible it was like he’d lost all his feelings for me and it took him about 2-3 weeks to come out of it but he stll hasn’t got any patience’s and snaps easily. I don’t know If maybe he likes someone else or if it’s because of something that happened months ago that I suspect hurt him deeply.