GB not everything that looks good from the outside is what it seems. He hasn’t had a personality transplant. Odds are he was NOT happy to find out he was going to have another child (a child that incidentally, due to parental age and family history, has a good chance of being autistic too).
He might also be in debt up to his neck with that house. A year from now he might be cheating on the new wife to escape the reality of diapers and midnight feedings.
Don’t waste energy resenting this “perfect” life you think he has, cuz it’s not, I guarantee you. Your life sounds pretty good to me, and you’re authentic.
My ex married a woman 19 years younger than him, and I mentioned once to my (grown) kids that I thought they might try for a kid, especially since she was adopted. My son was INCENSED at the idea of having another sibling forced upon him without his consent! (Fortunately they didn’t seem to have any plans to have a child as it turns out.)