After casual relationship...?

I wouldn't if i were you.It's been 5 years and now he is finally coming around.He just wants to use you like a piece of meat again until he finds another girl.He is desperate for anyone.He never wanted to be friends when he was with his girl right? He ran off and left you in the dust.You should find someone else who will treat you better.Don't let him get the best of you and ruin your life with drama and conflict.You have the basic idea at the end of your question so put that into play and stick to your guns.You WILL find the man of your dreams someday and this guy is far from being the man of your dreams.Being friends will just make the whole situation worse unless you can control yourself and not sleep with him again.