My 30f wife and me 31m husband have been together 9 years. She still snaps an ex. Should I be worried?

My wife would get snapchats from an ex of hers who has been sleazy in the past. She was in love with this guy and he broke her heart. I asked her to block him because I wasn't comfortable, she did for a while. Then a few weeks later she told me she wanted to unblock him and he apologized for treating her bad in the past and she told me and him she really appreciates the apology and wants to make it clear they can be friends but she is in a happy marriage with me and had 2 kids. I think they talk quite a bit now and it really bugs me but she doesn't seem to understand why and shows no intention of stopping. What do I do? Edit: we also have 2 kids together which just adds more variables to how I feel about it.