He's been hiding away too long. If he's being honest with himself, then he's aware of that; he knows it's not healthy (like anything their family does is healthy) to spend all his time in his room when there's people literally right outside his door asking to help.

He showers, gets something to eat from the kitchen, and goes looking for the sister he's been semi-ignoring for about a month. There's plenty of space in the house to go looking, but they tend to have certain rooms they use more than others, and he finds her in one of the living rooms.

He knocks on the door frame on the way in. "Hey, Cass. You busy?"