He wasn't taught to put his spouse first, his parents tought him to put them first...

Do you think it will be easier when they are gone?

Your H will go Mid Life Crisis on you for sure... And then the affair will start for sure too

Your husband never learned what marriage is... His parents don't even know for God's sake do they?

Do his parents bicker with each other at all? How does their marriage function?

This is what he will first learn from is them.