Couple dynamics and unconscious beliefs/expectations about couple obligations and individual freedom come up in some of these threads (often an avid diver with a non-diving spouse, so in a sense you're fortunate with what you've got). My wife dove a little before having our 4-year old, but she was a tropical aquarium conditions only vacation diver 'dabbler.' A few dives once a year would be plenty. And then my other buddy was prone to get sea sick and take long afternoon naps (disastrous in Bonaire when time's a waste'in...).
I took an SDI Solo Diver course, and that's been a help. But it's not an all situations cure-all.
Consider these questions...
1.) If you wanted to go on a solo trip, such as a live-aboard to do a lot of diving, or on an advanced diving trip, would that be a problem?
2.) If he wanted to go on a solo trip (to deer hunt, ski, watch a ball game in another state, hike, mountain climb, tour a museum, whatever he likes to do), and left you home, would that be a problem?
3.) If you wanted to go on a trip optimal for your needs (e.g.: had some deep wrecks, or cavern penetration, etc...), and instead chose a compromise destination (e.g.: tropical aquarium condition shallow reef diving), would that be a problem?
4.) Are you one of those 'big on togetherness' people, or is your philosophy 'Welcome to tag along, but no obligation to do so?' Do you think you're 'supposed to do' things together, and if so, like what?
5.) To what extent is the problem you wanting to do dives he won't be qualified for, and to what extent that you want to dedicate more (vacation time, money, etc...) to diving a lot and he wants to 'dabble' in it but do other things?
While some spouses take issue with their partner heading off unsupervised on extended trips to exotic destinations with opposite sex participants, there are other reasons people have issues with independent vacations.
Some destinations offer a mix; a Key Largo trip may offer the option for deep wrecks in the morning, shallow reefs in the afternoon.
Richard.