However apart from the sex, all other aspects of the relationship and family may be good.
So the guy has choices:
Stay in a sexless marriage and become celibate,
Divorce with all the pitfalls,
Have affairs with even more pitfalls,
Punt.
Punting is just sex.
It often does save marriages and has done for hundreds of years.
Take the word of the guys who are in that position.
That.
I'm happily married in the sense of sharing my life with someone I enjoy sharing it with, time away together, and with mutual friends, and having the family all together and harmonious at Christmas. After so long any sexual spark that was ever there has fizzled out.
I'm biologically wired to be attracted to women at peak fertility, this is a natural survival of the species instinct we all have, innit? And she's wired to retire her reproductive tract the moment she's churned out all the kids she ever wanted.
So in this situation punting works. I get to scratch the itch with someone I want to scratch it with, I'm saving Mrs a job freeing up time she'd rather spend watching reruns of Poirot, and a few WGs get to earn easy money servicing my otherwise neglected cock. It's a win all round.
I'm happier living the life I'm living than any of the alternatives I can think of. Thai brides, running off with younger women, affairs. It's all too complicated and I genuinely want to grow old with the wife. I've just as little desire to fuck her as she has to fuck me.