Is his profile pic with his ex gf a red flag?

I use this online dating app. Recently I have been talking to this guy, let’s call him M. We were having a good conversation, he seemed a nice and funny guy. He was also watching my videos. <br><br>Then I decided to look at his pictures. He posted this one picture with a girl. Her hair was longer than his so I immediately assumed she was a girl. She had her arm around him and he was blushing. He was wearing some sort of a t shirt and his shoulders were showing. They were sitting next to each other. Another picture of them was M giving her a hug and the girl was sitting on his lap. They looked like a loving couple. In the comments of the picture his friends were writing that they are going to miss them (the couple) and I asked his friends who was the girl in the picture. They said it was M’s ex gf. <br><br>There were more pictures like that and this girl was his profile picture for a long time. I am not sure why that is a big deal to me but I do feel bothered by this. Could this be a red flag? What does it mean?