what even is this abt

I’m guessing they’re actually a couple but there was some sort of accident he lost his memory. Instead of telling him who he is to him and making him feel like they should be together out of obligation, he decided to deceive him. So now dude thinks he’s just a human servant who’s just super strong but I’m guessing he’s also a demon. When the devil guy saw him getting done in by that slime monster her thought he was cheating on him. So now he’s angry