What is the relationship between the woman and the man?

M: When did we last visit this place?
W: I remember exactly. It was on our fourth wedding anniversary, four years ago.
M: How about swimming at the beach again? We should relax.
W: Don’t you think it might be a good idea to go there on Saturday? It will be our ninth wedding anniversary.
M: Great idea !
W: The children will be happy.
M: So will I.