So my ex and i are friends?

Yeah so my ex came back after 3 years married with a 3 yr old son. I broke up with him 3 yrs ago because i didn't love him. Anyways he is back now honestly i am sexually attracted to him and i have know him since we where kids. So yeah i said no i just want to be friends he kissed me but so far we have never had sex thank god. Anyways he is married but they are no longer together and he works for the military/ health insurance coordinator. I told him i don't have feelings for you and i love someone else...and i told him i hate guys that try to kiss and touch me and skip the whole friendship. So yeah he says oh okay i understand and i will stop...So now i don't know my question is am i dumb to think i can train him throw being his friend on how to treat woman? Or i should just be like **** it he is a lost cause? or he is just putting up an act?