This is one of those internecine familial dramas that at times is really quite preposterous, but is also quite observationally funny. First, there's "Joe" (Woody Allen) who used to be married to "Steffi" (Goldie Hawn) who is now married to "Bob" (Alan Alda). She has two daughters by her second marriage and he one son by his first - a entertainingly died-in-the-wool republican in this nest of liberalism! Then there's…