Need advise!!

I have my own business in which my ex’s family is a client of mine. I have no communication or relationship with my ex. My current boyfriend feels uncomfortable and doesn’t want them involved as fear of the ex showing up or communicating with me. I feel horrible having to fire them as clients but I’m also so tired of the arguments/comments this has had on my relationship. I don’t want him to feel disrespected or uneasy.

What would be an appropriate way to let them know I can’t continue this relationship with them and they need to find services elsewhere?