This may be confusing and I'm sorry, but stay with me
My fiance dated a girl about 3-4 years ago, where she broke up with him once then the last time he broke up with her. I know he truly loves me and has never given me any reason to think he doesn't nor has he ever given me any reason to think he'd leave me for her. However, he's been best friends with her brother since they were about 3 years old, so he'll be the best man. He's grown up with their family and is friends with the rest of the kids that are around our age. Occasionally she'll comment something on his facebook pictures(to which he doesn't reply) which makes me feel really insecure and jealous for some obviously dumb reason. I trust him, I just don't trust her because she has a flirty personality with everyone, even though she's in a relationship herself.
Since we're inviting her family, do we have to include her too? I really don't want her there as I think I just get upset thinking about her. I know I am jealous and insecure, but I just don't know why. I know he loves me, since I am the one he wants to marry. What do I do? WHY can I not get over the fact that she's just an ex?