Perhaps slim but there is a chance his wife is living her best life. Healthy children, unlikely to have financial worries, married to her best friend, can have discreet affairs/hookups whenever she wants...
For some it will be untenable of course, but for others the trade-off would be worth it. We’ll never know. And sexuality is fluid, I’ve no doubt they love each other. And I’m sure it would have been clear that at some point he would need to play this trump card.
It all comes down to how open and honest he’s been with her and how much input she’s had into the finer details of how their marriage has worked.