I totally agree to the best friend thing.
This is exactly what I have been trying to tell my hubby of 11 years!. We have 2 kids but there is nothing between us. We hardly think alike on any subject on the earth.Also we are going thru a lot of career crisis and I feel hardly any interest in sex.But for him sex is "like brushing your teeth- you just do it" Unfortunately it is not so for me and I want my partner to understand me, my needs and my worries before I can share my body just to "please" him. He thinks that I have too many pre requisites for sex but He is has changed so much that I cannot identify with him as a friend, let alone best friend.
And he measures everythihng ont he basis of sex.If he is happy ( after we have sex)he will do his duties around the house and the kids. If he is not then he just sulks - no going out, no doing chores, no meeting friends, no socialising nothing. This is affecting my relationship with our common friends and I cant explain to everyone why we pull out of pre planned events at the last minute. Some places I do go alone but it does get uncomfortable and I have to answer too many questions abt "hubby not being there"