Letting go of an Ex


I’ve been hanging out with an ex (knowing he likes me but I don’t want anything more) – but recently met someone that I may potentially date. BUT they know each other.  I want to tell my ex that we can’t keep hanging out – since I want a relationship with someone and that won’t happen if I keep hanging out with him- but I’m afraid how he will react…and if he finds out it’s a friend of his…