What is the relationship between the two speakers?

M: Have you seen my school bag, Mom? I’ve been looking for it everywhere.
W: I hope you didn’t leave it in school. You never know where you put your things. When did you last see it?
M: Last night before I went to bed, I think. I remember putting it on the desk.
W: Really? If you put it there, it should still be there. No one has been to your room. So it must be here somewhere.
M: Yes, but where? That’s what I want to know. Oh, dear, it’s about the time for the school bus.
W: Hey, what’s that under your blanket at the foot of your bed?