Jon very pointedly and loudly closes the door, because he's a fucking teenager and having petty fights with his grandma is his lot in life. As expected she didn't call up or say anything, he figured she was just trying to get a rise out of him. Guardians are the worst and no one understands the hard life of teenagers.

With one last nasty look at the door he finally turns to Martin, embarrassment flaring up again. "I uh- sorry, she's-" God. He reaches up to push his glasses to his forehead and rub his eyes. Such hard teenage problems. "She just likes to pick fun at me, she's not- it doesn't matter."