Welcome to the most awful party in the world. Your host - it's his 40th birthday bash - is Hector, an immature but married Greek-Australian who, as middle life arrives, cannot shake off the vices of youth or stop thinking with his penis.
His wife, Aisha, an Australian vet of perhaps African or Caribbean background, is a dedicated mother but demanding spouse.
There are Hector's parents, Greek immigrants by origin but also cliche; and his sister, a socialist. There is Hector's prosperous cousin Harry, a self-satisfied fellow who sends his children to private schools. There is the Muslim couple, there is the TV soap writer and her boyfriend the soap star, there is the girl who works at Aisha's surgery; she is babysitter for Aisha and Hector, and his sexual fantasy.
There are others too, but the worst guests of all are the slack parents: Rosie and Gary, and their 4-year-old (perhaps 3) son, Hugo. Rosie still breastfeeds Hugo but lets him run riot. Gary likes a drink. Then another drink.
At the most awful party in the world, all of these people drink too much, bicker, flirt and, in the party stopper of all party stoppers, during a game of backyard cricket with the other sprogs at the party, the naughty, brutish, awful Hugo waves the bat about in a dangerous fashion before kicking Hector's cousin Harry as he tries to remove the bat from the boy. Then it happens: Harry hits Hugo, in the face, with an open palm.