I have a husband who has a wife who gets obsessed with things.
I have ADHD and can hyperfocus to Olympic Gold Standard.
One of the strategies he uses was discovered by our son. If you put a hand on me (like the back of my hand if not currently in action, my back, or my shoulder) before trying to verbally get my attention, and keep it there both when you finally get my attention and while you are speaking to me, it helps me come back off the Hyperfocus dragon I'm merrily riding. Temporarily anyway.
The other way is also perfectly reasonable when I don't respond the the above. Pointing out that it is unfair and unloving when I make zero effort to rein in the hyperfocus dragon and zone out of the family to indulge my gallop.
I do not have amazing control over it. Yes. Especially if they don't catch me at it in the early stages of a new gallop off with the fairies. Most of the time I don't even know I'm doing it until it's too late and I'm in too deep. It helps me a lot if my family intervene at the early stage when I have a better chance off hauling myself back out of it. Waiting until it is well underway puts both them and me at a disadvantage when it comes to forcing a dismount.
But I've discovered I have way, way more control than I used to have when I didn't know I had ADHD and wasn't actively trying to control it. Every time I have valiantly tried to pull myself out of it I have got better at it and more successful in doing it quicker, and less grumpily. It has been hard work, especially since I love being hyperfocused on something. But as much as I throughly enjoy being in that state my life, and the lives of my family members, have been so, so much better since I started working on developing brakes.
I'd rather my husband got cross with me than suffer in silence and develop issues of his own as a consequence. I love him and don't want to make him unhappy, or worse. I wouldn't want him to get to a point where it became unbearable and he started to see our relationship as lost, or untenable either. So I have been, and would be again, willing to engage with whatever professional help was available to give me an edge in keeping the ADHD under tighter control so I don't negatively impact the people I love most.
I have a condition. I do not have a "get out of jail free" card that gives me carte blanche to discount everybody else's feelings, needs and desires. They are real live humans too, not bit players providing a foil for me in a screenplay of my life, featuring me +ADHD as the lone protagonist.
I may have a thing that makes life much harder than it otherwise would be. But it doesn't come with a responsibility placed on everybody to sacrifice the things that matter to them, or their mental/emotional wellbeing, in the name of me being a factory second so my feelings/issues are the only priority anybody close to me is allowed to have.
Does he have a diagnosis where hyperfocus or obsessive tendencies are often a symptom ? Would he be willing to be assessed ?