He lost his father at a young age and doesn't get to see his own mother often. I wouldn't expect him to act any different than he did last night.
Make a post saying you wanna talk about the situation and be patient with him. He may be older but he doesn't have a strong emotional hold. He'll try to understand your side of the story if you talk it out with him properly.
Just don't use his condition as a way to damage him if he refuses to listen.
He's a nice guy, he just has a bad upbringing.
I'm sure you'll understand and try to talk to him.