You still feelin possessive over the ex but that’s over. How many steps of distance are ok? Second cousins best friends daughters work mate who saw you dating him at a club once ok? 1 reply
I don’t think you should be mad at her since she’s not that close to you and she probably doesn’t know the details of how the relationship was between you and your ex (besides knowing that you dated). You can cut contact with her if you’re upset over this though reply
If it bothers you, you should cut contact with her and block her on social media. I do find it weird that your friend didn't tell you that her sister is dating your ex. But the sister really doesn't have an obligation towards you. The sister is not your friend. So if the whole situation makes you uncomfortable then cut your friendships and move on,...... reply