Should I still be "friends" with my ex-wife's boyfriend?

My ex-wife has been best friends with a guy for 14 years, and they've been dating for about 4 months now. When I was dating/married to my ex-wife, I got along with him enough to consider him a friend. I currently have him as a "friend" on my Facebook although I feel as if he represents someone far from being a friend. I feel as if I grossly mistook him for an actual friend, and as someone who just tolerated me in the time I was with my ex-wife. Not too long ago, I had asked him if we were still "friends" (I meant it at the time), and he said "I'd like to rekindle our friendship. Needed a little time to re-adjust with your moving and everything that happened", which was about 2 months ago. I feel the need to tell him on his Facebook wall exactly how I feel about us being "friends" and how I feel he was just tolerating me rather than being a friend, and to tell him that we shouldn't be "friends" anymore. Should I just let this go and see if he does still want to be friends, or should I give him a gentle reminder/express my true feelings?