Book excerpt: A big sister is horrified when she can't fit into her swimming costume. Her BOTTOM IS SOO BIG! But her little sister has some good advice. There follows a wonderful romp through history and fairyland, as the little sister explains exactly why a big bottom can be useful. Father Christmas needs one for crash landings and, if you are a queen, a big bum is vital to keep you comfy while sitting on your throne . . . Once again Nicholas Allan combines laugh-out-loud humour with real insight that cannot fail to raise a smile.