It's biological in nature; women go for the BEST man they can get at any given time, men go for as much female companionship as they can get.
point him at this link
https://www.reddit.com/r/TheRedPill/
keep him off the bitter side of interpretation tho; a lot of guys go into that broken hearted and pissed off at women instead of just recognizing how life is and not how they want it to be
Thank you for the advice, that might work better than what I am trying; currently I have him chained to the fence outside and every time he starts crying over this woman I go out and slap him across the soles of the feet with a short length of electrical cord till he promises to man up and stop whining on this woman...
After two days maybe he is ready to try some other form of " therapy " . . .
LOL
btw, "GFTOW means Go F**K Ten Other Women"
hopefully he likes that better than you beating on him with electric cord.
you might end up with a much worse problem on your hands!
I did google that ;)