'You don't really grow up until you either have a kid or one of your parents dies.' Glamorously carefree and nearing forty, Tess shows no sign of settling down. That is, until she drops a bombshell on four of her friends: she's pregnant, and has chosen them as godparents. Yet while they rally round the single mother, each one is struggling to face the realities of adulthood. Sierra may be only twenty-three but her mother is so irresponsible that she's had to grow up fast. Michael is too busy searching for Mrs Right to worry about collecting the essential accessories of spice racks or investment saucepans, while Owen eases the pain of a mid-life identity crisis with a string of unsuitable fiancÃ©es. Only Lucy has the trappings and offspring of a proper grown-up, but is terrified of ageing. On a challenging and hilarious journey through birth, Botox, bad sex and beyond, all five friends must discover that while growing old is inevitable, growing up is optional . . .