A new book reveals the sordid details of extraterrestrial sex.

Alien

Alien

The tome called 'Screwed by the Aliens' is full of stories of people who believe they've slept with UFOs.

According to Metro.co.uk, it includes stories such as people who claim that their alien sexual partners are the best they've ever had, a man who claimed that aliens inserted a 12-inch 'living' probe into his anus, and some claiming that aliens disguise themselves as celebrities to have sex with gullible humans here on Earth.

Nigel Watson, the author of a chapter in the book - which is edited by Timothy Green Beckley - claims the first documented sexual encounters with aliens happened in the 50s.