is my sons behavior normal?

The wife's a bitch who has put her own spin on his childhood by trying to psychoanalyse why you did things - and she hasn't a bloody clue!! She hasn't had to sacrifice anything. It's probably just easier for him to nod and smile so as not to rock the boat with her. It's her he has to live with so it's easier for him to choose her over you.

I know some extremely dominant wives who have done this with their husbands and I think it just comes down to their own insecurities and jealousies. It's ridiculous coz we expect the men to stand up for themselves but in reality they just keep their mouths shut.

This is very sad for you, but you're going to have to shrug it off as there's nothing you can do until he comes to his senses. Don't let the witch see she's managing to hurt you coz that's what she's trying to do!!