with my ex, I was like "I'd love to stay friends, but you were such a shitty boyfriend that if you want to maintain a friendship, you're going to have to be the one doing the hefty lifting."
surprise surprise, never happened. the biggest problem in our relationship was that he was never there... he compartmentalized everything in his life so much. he could see his family, see his friends, or see me, but the three sides of his life could never be intertwined. and he worked such long hours that all he'd ever want to do after work was go home and go to bed (alone) unless I really nagged him about going out or insisting on coming over to cook him dinner.
I really wish we'd met under different circumstances... we probably would have been great friends / occasional fuck buddies without the burden of trying to maintain a relationship thrown in. but as it was, I felt like I was single but forced to wear a chastity belt during the relationship.