Now we don't want to start Christmas like this, do we?Cheating at snakes and ladders, fighting over comic books, a bungled infidelity beneath the tree. Christmas has arrived in the Bunker household along with family and friends. But as the children lurk just out of sight, it's the adults who are letting the side down.I couldn't. Not in our sitting-room. Not in front of the television. Somewhere else. Presiding over the festivities are two warring uncles, one a kindly, incompetent doctor with an interminable puppet show to perform; the other a bullying retired security guard who dominates the TV, brings toy guns for his nieces and determines there's a thief in their midst.Alan Ayckbourn's masterly Season's Greetings offers a seriously entertaining look at the misery and high jinks of an average family Christmas. The play opens at the National Theatre, London, in December 2010.Three times I caught him at it. Ripping open presents, helping himself to the contents.