In another frank look at the world of sex, the Sex Survey reveals how many Brits have had a threesome, and in which part of the country people are most likely to have cheated on a partner.The roadshow travels to Angmering School in Sussex, where the pupils are taught everything they need to know about genetics. From penis size to height, and skin tone to breasts, the kids learn with the help of two naked families how genes determine where we get our size and shape from.They are taken out of school to be taught about breast health at a unique breast research centre, and also get to discover the highs and lows of first love from their parents and grandparents in embarrassing intimate conversations.The show meets Nicole and David, who have overcome Nicole's physical disabilities to enjoy great sex and, against the odds, conceive a child.