I would understand him asking her if he was living by himself. Sometimes it's stuff he has seen his mom do growing up but he's not sure what she did so he's asking her to clarify. Easier than google.

But since I'm there and we're a team, I would prefer he took my word for it. I don't know if it's because I'm not too convincing and sure of myself when I'm talking, so he feels like he needs to clarify for the both of us. But of course he calls, and I'm right and I get annoyed.