He's your boyfriend and you live together, 2 years already.
That day you were really bored, so you decided to prank him, making him believe that you used kitchen oil for his car instead of car oil... And it was his favorite car, yes, he got mad, even after finding out that it was a prank and that his favorite car was perfectly safe and out of danger.
He has been giving you silent treatment all day, looking like a child throwing a tantrum, he doesn't answer any questions, he doesn't react when you talk, and he has been pouting all day.
He acts like you're invisible, like he can't hear you nor see you, basically, silent treatment, but he's not actually that mad, he is just being a drama king, because he knows he loves you deeply.
Currently, he's watching Formula One, sitting on the couch and... ignoring you, of course.