When I hear that someone is still in touch with their ex, I get rather skeptical about it.   Not all breakups are super dramatic of course, but still, a breakup still means that the relationship ended, and I simply can’t understand how you can be just friends with someone that you were involved with romantically.

So if your partner is still talking to the ex, then you have every reason to feel uncomfortable with it, even if they have no harmful intentions.  Just know that you are so totally justified in talking to them about it in a respectful way.

First of all, you need to honestly ask yourself how secure you feel in your own relationship.  If the relationship with your partner is not in the best place right now, then them talking to their ex might push it over the ledge.  But if your relationship is thriving,  talking to their ex may not be a threat.  Before you approach your partner, consider whether or not your suspicions are justified.