FACTUAL The Secret Life of Four Year Olds, Channel 4, 9pm
Tonight in the not-so-secret secret lives of these loveable four-year-olds, it's all about romance. After Harper works up the nerve to propose marriage to his girlfriend – despite not knowing her name – his best friend Vinnie isn't happy. He has his own girlfriend, but that is no matter. Vinnie and Harper are meant to be best friends, with or without the girls. Watching the children play at democracy and peace-making is as fascinating and, as always, very cute.