Bathrooms, Doug found, were like little safe havens. You quickly stock up on drinks and snacks, ignoring others even if they call out to you, and then go to a place with a sink, bath, and toilet. It's like a mini home! If someone comes to the door, say you're using toilet. If some else comes, say you're throwing up. If someone wonders why you've been in there for so long, say you're someone else. The house had two bathrooms anyway.
The only reason he was here was for a similar reason to Chell's, except it wasn't working out too well. Plus, who wouldn't want free food, drinks, and a little den to hide out in?
A/N: Halfway through writing this chapter, I realized that the bathroom was basically like his little rat dens in the games. Just a little fun fact about my subconscious doing my work for me.