Mid life crisis males, but it's harmless fun, everybody else does it, I've had a clean sheet for all these years, whether it be lap dances, camm girls, prostitutes, emotional affairs and physical affairs.
Something tips the balance in them, whether it's the dimishishing figures and looks of their wives, their apparent fear of getting old and their own emortality, god knows but one thing is for certain they do know how hurtful this behaviour is.
Where it becomes not only hurtful but cruel is when they do it on purpose, I have known men be like this whereby there is unspoken resentment.
This type of behaviour changes things, for good and many men can't understand why forgiveness is not forthcoming, they believe to be loved is to be forgiven for anything, "look how long we have been together why would you throw it all away."
He had a very supportive wife in op, a shared bond that was special over many years and now the rules have changed. Op this will affect you in so many ways you won't even have thought about but have a think about what you feel you need to do for him now.
He is no longer entitled to that, as one poster once said platinum star treatment, he's on the bargain bucket tin treatment.
Do what you want to do and pull back on help for him, he doesn't deserve it.