Everyones advice seems so questionably specific, I think its great questions to ask regarding "growing amiably apart" its a great catch and feel i am int he same boat. i might have to ask that question to my husband too and see what the response is.
I think a lot of marriages die a slow death, partners "growing amiably apart" if lucky, "angrily apart" if not, but eventually reaching a point where at best they are roommates and parents. Careers, kids, financial distress, illness, in-laws, parents - all of these make for more separation, the seven year itch is apparently real, and if the couple gets through the seventh year, they start another cycle.
Marriage is not easy, I for sure don't understand it, a contractual relationship for much of human history has become a romance novel. What do we have as examples of behavior - actors and actress with more money than brain cells playing musical beds every few years, their beautiful faces surrounding every grocery store checkout lane, rich men divorcing wives, replacing them with arm candy, all of us driven to be happy, successful, sexy.
Differences in libido happen all the time, the high libido partner feels rejected, is unsatisfied, the low libido spouse feels called upon to have sex way too often.
I'm willing to bet in a lot of these cases there is some talk about unmet needs and wants, one partner will say "I'll change" or react angrily. More often than not the changes don't last long and sooner or later one or both are confiding in friends - "I want a divorce".
I have no idea how this can be avoided. I'm in a boat, w is in a different boat, we are going in different directions. Ahead and behind my boat, I see other boats, each with one person aboard, some are going in circles.