Tom Cruise had an "intense affair" with 'Risky Business' co-star Rebecca De Mornay

In his soon to be released memoir 'Revenge of the Nerd', the 63-year-old star wrote: "It's no secret that Tom engaged in an intense affair during the shooting with De Mornay. Returning late one night, I found three or four young girls - late teens, I suspect - lined up in the hall outside of Tom's room.

"I remember thinking 'Tom's going to be really upset if these hot girls interfere with his Bible reading'. So I asked them, with all the stern gravitas of my 28 years, if there was something I could do to help them.

"They just stared at me and at that moment, Tom's door opened and another girl came out adjusting her hair and taking off down the hall, while the first girl in line slipped into Tom's room.

"This was a young man who knew something about time management and understood how to successful juggle Bible study with blow jobs."

'Risky Business' follows Joel Goodsen (Cruise) who hires Lana (De Mornay) for a night of delight when his parents go on holiday.

However, the morning after Joel is shocked at Lana's "bill" and resorts to turning his house into a brothel to raise the money fast.

At the time of shooting De Mornay, who was 23, was already in a relationship with 'Repo Man' actor Harry Dean Stanton - who was a lot older than her - and despite her affair with Tom not being 'exclusive', Curtis believed there was a hint of jealousy.

Curtis wrote: "I suspect that most of Harry Dean's great qualities were lost on Tom who, I think, was beginning to regard him as a guest overstaying his welcome."