This is true, but he did lie to everyone about graduating from college. What this before or after his marriage? If they were married when he lied about that, it would bump your theory. She could be an evil witch, and do just what you said she did, and it could explain MH's episode at the motel. Let's wait and see what happens. Anything is plausible at this point.
Your relative and my ex would get along splendidly. I don't want to go into the TMI territory, but unfortunately I have years of experience dealing with liars.
Wouldn't it be great if all the liars and manipulators of the world got stuck with one another. That would be fun to watch.