EX BF TROUBLE!

Basically my ex boyfriend and I were together for a year, however we still "hang out" and things always seem to escalate.... 
Thing is, I have a massive crush on this other guy and we have been hanging out here and there.. but still feel so connected to my ex. 
I keep telling my ex I want to stay friends with him but he is so "in love" with me that he says it's too hard. I don't know what to do! I want to stay friends with my ex because he has such a beautiful heart but I see potential in this other guy and seeing them both doesn't help!