Why do guys with girlfriend use tinder?

A friend of mine told me they saw my live in boyfriend on tinder. I set up a fake account. He was. He's deleted it since as apparently my friend told him she'd tell me if saw him on it again. The pic I used was of a girl I knew he'd right swipe. He did. I tried to talk to him but got no reply. My question is why is he doing this? Fact he ignored fake profile of a girl I made up to be just his type despite matching made me wonder why. I know from my own experience it is not that unusual for taken guys to be on it. For example, one guy said to me back when I was single and using app as myself that he was going on holiday with his girlfriend but it was rocky and he'd love to take me out when he got back. I unmatched him straight away. Me and guy I'm with aren't rocky. I'm wondering why he did it
Why do guys with girlfriend use tinder?
Add Opinion