i was often disappointed. it may seem trifle, but i felt i gave so much that went unrequited.
i know now that he was battling with so many inner conflicts that he couldn't reciprocate to the degree that i needed. it weighed on our relationship. then when he da-ed him, it was my turn to disappoint him. i could no longer reciprocate to the degree he needed. we hardly talked anymore (which was our marriage's foundation).
we decided to seperate.
we stopped being mates and became best friends again.
and that's where we are now, best friends.
(and then of course, there are the degrees of dopamine and oxytocin in every relationship that will inevitably affect whether there is a breaking point or not).