My friend and I are having a shared birthday party. This is what I've got so far (not real names of course):
You are invited to a party to mark the occasion of Joan and Maxines shared birthdays.
Now. Is it "Joan's and Maxine's"? Is it "shared birthday"? I've spent far too long pondering this and the invitations need to be out (not convinced friend will get it right either...). Please, please help and I'll send you some cake