Hello, I'm male 45yrs and can identify with this issue.
During periods (weeks, sometimes months) of stress I found I struggled to cum without using my hand.
Certainly I would agree that it's a case of reverting to a familiar way of getting off, but not because I was too attached to my hand. I had been married for over 18yrs and we were very active sexually.
For me the fact that my wife expressed concern at this odd turn of events simply added to my stress. I knew she didn't intend to, but that was the effect.
When we talked about it and I explained about the causes of my stress, usually work, and that she was in no way to blame (no one was to blame), then things became easier for both of us.
We still had sex of course, but it was understood that until I'd resolved my work issues I would have to finish myself, which I did after a short time.
In a sense I was lucky because I'd been in such a long and trusting relationship, if I had known her only 2 or 3 months it may have been different.
I guess what I'm trying to say is that the problem is an external thing to your relationship so certainly don't blame yourself (or him), just reassurance and patience all round will do the trick.
This is obviously from my personal experience, but I don't think I'm unique
