Bill Wyman regrets his controversial marriage to Mandy Smith

Speaking in the documentary 'The Quiet One', which premiered at the Tribeca Film Festival last week, Bill, 82, said: "It was from the heart. It wasn't lust, which people were seeing it as. I was really stupid to ever think it could possibly work. She was too young. I felt she had to go out and see life for a bit."

'The Quiet One' is written and directed by British filmmaker Oliver Murray and features footage and photos from Wyman's time with the Rolling Stones.

Mandy and Bill married in June 1989 but separated two years later.

Although Mandy had maintained they had waited before starting the sexual side of their relationship, years later the model claimed they first had sex when she was 14, below the legal age of consent in the UK which is 16.

And a pal of Bill's recently admitted she was "ashamed" that never challenged Bill over the "illegal and immoral" relationship.

In an extract from her book 'Tumbling Dice' published in The Times newspaper, writer-and-journalist Lesley-Ann Jones said: "It was an illegal and immoral relationship. It was accepted, and blind eyes were turned. The perpetrator was an A-list rock star. I am a mother of a son and two daughters. I turned a blind eye too. I am ashamed."

Lesley-Ann has admitted she will always be "tormented" by the fact she never said anything to Bill at the time because she knew their relationship was wrong.

She said: "Some memories torment us, despite our best efforts to forget them. My guilt is hinged to the things I never said, but really should have.

"Because I knew a grown man who was having sex with a child. He was, in those days, my friend. His girlfriend was under the age of consent. The law on this in the UK is clear: if an individual over 18 engages in sexual activity with a person under 16, he or she can be charged with a criminal offence, which may result in a 14-year prison sentence. I was aware of this at the time, but I did nothing."

With hindsight, Lesley-Ann believes Bill deliberately gathered a "clan" around him to hide his romance with the teenager.

She recalled: "Only all these years later must I admit to myself that Bill was gathering a clan to conceal his love affair with Mandy.

"When his limo approached our chosen restaurant for the evening he would say to one of the boys, usually the tall, dark-haired, good-looking one who grew up to become a famous broadcaster and writer, 'Would you mind walking Mandy in?' He would then take my arm and beam for the photographers, snuggling up to me as we emerged from the car. At the end of the night, when the car dropped us off, it would always be Bill and Mandy left in the back."

The group only discovered how old Mandy was at her 15th birthday party and they instantly "scarpered" from the couple - but they feel they were "as bad as Bill" for not challenging the situation.

While Lesley-Ann believes Bill when he said he had no idea how old Mandy was when they started dating, she insists he should have immediately "backed off" when he found out the truth.

She wrote: "The minute Bill discovered Mandy's age, he should have backed off. He would later shrug off the whole tragic episode as a midlife crisis. He got away with it."