Coming to this thread late because I didn't know it was here, but I have a very similar story that happened to a the mother of a childhood friend of mine and she only found out 3 months ago. Her husband has left her.
It wouldn't surprise me if Phil had been getting his rocks off for a while because the story just seems *so*similar to that of my Mum's friend. Let's call her K, the husband S, and the person on the other side A.
My friend has a younger sister. Let's call her N. N was 15 at the time when K found a phone lying around. K had presumed that the phone belonged to a friend of N and so gave her the phone in order to find the rightful owner. Said phone had, shall we say, a lot of dodgy messages from someone called A and when N confronted her dad S about it, he basically admitted that he was gay, and made N promise not to tell her mother.
This poor child had to keep her Dad's closeted secret for 15 years while the affair continued.
Fast forward 15 years. N is now 30+, none of the children live at home. They are both retired. K is now 65+ and S "suddenly" comes out and leaves home shacking up with the other guy. K says that so much stuffed clicked into place. Things that had made no sense to her, regarding sex life, "work" time away from family, endless sporting trips, etc, suddenly made sense.
Everyone including mine, has the attitude that if the dude's gay, then he's gay, and there's really not a lot anyone can do about it. Better to come out than not at all and the kids haven't been particularly effected, they have left home after all and have their own families now.... but
I do not think any of this is particularly brave. It has been devastating for K who at 50 years old when N found his phone could have still moved on (had S done the decent thing then), but instead she continued being his housewife and gave up her career to raise his kids, she was totally dependant on him (he is very successful in his field), and basically feels like she was used as a prop in his life. They were together for over 40 years, and she is coming to terms that that 40 years was a sham. She's also pissed off, rightly IMO that any hope that she might have had a semblance of a chance at finding a fulfilling relationship at 65, with a man who loved her in the way she wanted to be, is basically nil, and that she had no choice in the matter because that choice was taken from her.
She now faces the last years of her life in a big empty house. Alone. While S pops around to check occasionally that she is OK and then goes back to A.
S says that everything they worked towards in the marriage, all the material success they build together is still theirs and A won't have a dime of any of it.
A saving grace I suppose.
Either way, I can't help thinking the dude is a massive arsehole. Gay or not hiding your affairs for 15 years? Expecting other people to cover for your secret while you take full advantage of the woman in domestic servitude at home, who raises your kids and cooks your meals while you swan about, completely out of the closet in one area of your life but keeping it a secret from the person who is raising your kids, lying to her, and then expecting adulation while you leave her to the last 10 years of her life alone with no one?
Get to fuck mate.
At least Phil didn't leave it 40 years, but still, his poor, poor wife.