Should you ask your man if he still talks to his ex?

I found out my man was still talking to his ex. I believe that exes should stay in the past and asked that he not talk to her anymore. I found out they still talked and got mad yadda yadda yadda it’s been awhile since then and I’m curious if she ever reached out again. It still bugs me how often they talked, how dirty it was and flirty. I don’t know what to do. It’s just bring me peace of mind i guess