Y’all- i need advice

so my bf and I are in love and I feel confident with where our relationship is rn. I think he’s serious about me and I really know he means it when he says he loves me. so literally as i’m typing this i’m watching him stream his video games and I saw on the screen that he has his ex (of four years) still added as a friend on there.

I know the relationship ended but it always made me insecure that she was into video games too and was more of a tomboy where i’m super girly. just seeing that made me kinda sad. I know they were childhood friends and I really want to hope they don’t play video games together, I think maybe it was just never undone like I really don’t think anything shady is happening. he doesn’t know that I know her full name so that’s why I can’t mention it. I just need some reassurance from y’all that it’s okay.