if you can be friends with 0 expectations...that means you are ok with just being friends, youa re ok listening to his life story as just freinds, you are ok with nothing more
then
be his friend
if you are being his friend with the hopes of being something more later...then don't do it
there are too many stressees in life to try to add that one to it
ther are so many other things to focus on
and you don't want him back, truly, if he is back because he feels guilty