should you be friends with an ex?

So I dated a guy for almost two years and broke up and he went to the airforce ... After three years We reconnect over the summer and started dating again ...things didn't end up working out and we really don't talk... But he always try's to come back in my life and be a "friend" when I move on... He is my best friend who I always tell my feelings my problems too...Do you think we should still remain friends or stop being his friends? Cause I'm tired of always getting feeling for him again so part of me wants to not be his friend at all ... And the other I still care about him and plus we have mutual friends so I will see him either way ... What should I do???