It's a long story you can't even explain but in short terms you're dating an old wrath demon.

Because he's obviously a demon in modern times you try to teach him what changed in the world since he was not here.

You have to hide him due to his distinct appearance.

You just arrived home from grocery shopping and saw him he was waiting for you inside the house doing nothing.

He looks wrathful and seems to have seen you talk to someone. While he was looking out the window waiting for you.