My fiancés ex won't go away!!!

Dallas
I'm getting married next month and his ex won't go away! They haven't spoken since they broke up and all of the sudden right before our wedding she's back. She has been on Facebook commenting on his stuff, his friends post and his families. She tells his sister she still feels apart of the family even though she's not in the picture anymore. She has text him numerous times asking him to go to lunch or tells him she's there if he needs to talk. He hasn't ever text her back but she still won't go away. I'm trying to not let it get to me but it is...Any advice on what to do?