If you hadn't of dropped 'hints' you wouldn't of been invited so I'm guessing they felt pressured and invited you.
Then originally it was just 2 of you, then you invited your son without checking it was ok with them and you expected her, not your son, to cook and host for all 5 of you.
Do they work? Are they renovating? Is she not a hosting type? Is the house a mess?
There seems like there's more to this especially because of your son's reply.
Do you buy yourself an advent calendar?
4-6 weeks wait for a routine gp appoinment.
Twenty pounds ! What will you receive ?
Old-fashioned pulley clotheslines
Change the name in a tv show /movie title to the above user username


