Is Your Best Friend Dating Your Ex Boyfriend?

I don't know many people who would be okay with their best friend dating their ex. You are absolutely entitled to have those feelings. That's exactly what anyone would do. I feel like unless unless somebody was in a relationship that was one of those ones that were not as significant and then you don't think about it again, then it might not be as much of an issue. But because it seems like he meant something a lot to you or whatever. Of course. It sounds like you had more of the first one.