I feel sex should be something that is determined by both partners and as you stated, it has to be mutual.

And sometimes we have to understand that just because one partner does not want to have sex, it does not have to mean something bad.

I am learning this myself as he ages - use to get too "emotional" and when he tried to explain, did not want to hear it(lol).

Now I do, and when we do have sex, it is extra special and meaningful. I no longer keep track of how often at age 53...