This programme explores what happens to people who see their twenties as a time to play the field and explore sex with many different partners.

We meet a 25-year-old man who enjoys sex so much he will sometimes sleep with four or five different women a month, and we follow a young bisexual man who regularly uses smartphone apps to hook up with other men for no-strings sex.

We meet a young woman who feels she lost her virginity late, but is making up for lost time. She explains her views on the perils of monogamy and the enjoyment she takes in pursuing sex with multiple partners, and we follow her and her friends on their quests to satisfy their urges in London's vibrant nightlife.

We also explore what happens when people never experience the drive to have sex, through the story of a young woman who describes herself as asexual, despite the fact she is in the first throes of a romantic relationship with a new boyfriend.

We look at the darker side of sex as well. For one girl, a new life in a new city became a sexual adventure taken too far when her promiscuity started to fuel feelings of depression. We also hear how a one-time encounter was all it took for a gay man in Ireland to contract HIV.

And we explore how new scientific insights into why we crave and enjoy sex help us understand the sexual choices we make at this stage in our lives. Show less