The roadshow visits Bishops Gore School in Swansea, where pupils get a full-frontal lesson on the subject of attraction. Three couples - gay, straight and lesbian - reveal what it is that attracted them to each other in the first place. And the show reveals the science behind falling in love. The pupils are also taken out of school to a sexual health clinic to learn about contraception, while the parents are taught about the risky activity kids get up to with sending sexual texts - or sexts. And the Great British Sex Survey reveals the nation's favourite sexual position, and how many British men have caught crabs.