What is the probable relationship between the two speakers?

M: Is there anywhere you’d like to go this weekend?
W: Nowhere in particular. Do you have anything in mind?
M: Well, John and I are going up north. Would you like to join us? We’re going to stay at Mary White’s.
W: Is there enough room for everybody?
M: Sure, there’s plenty of room.
W: In that case, I’d love to. Thank you very much for the invitation, Bob.
M: We’ll start tomorrow. How’s that?
W: I am starting to feel excited about going. What should we wear?
M: Bring warm clothes.
W: Anything else?
M: Not really. Maybe a camera if you’re interested in taking some photos.