How to deal if your friend remains friend with your ex?

After a year I have no contacts with my ex and we still are uncomfortable when we casually met, but my friend remained friend with him. It's like they know something I don't , cause she barely never talk me about him , as she thinks I'm uniterested, well honestly I feel quite left out, like I cant understand them anymore ... Is it normal to feel this way or should I talk to my friend?How to deal if your friend remains friend with your ex?
you just feel jealous you cant help it and i hope you wouldn't act on it just cause you dont like your ex doesnt mean she cantHow to deal if your friend remains friend with your ex?
My friend had this problem with me. Honestly , don't come inbetween it. You'll ruin two friendships in the end and it'll be a really bad ending. Yes , it's gonna hurt seeing your friend and ex playing around , maybe but be mature and just deal with it. That's why he's your ex. Don't stop them from being friends just because you can't handle it.