Grandmother Jo Roffey is to make her most intimate moments public in a television documentary.

The 60-year-old will appear in a programme on the secret history of sex and marriage, to be shown next week.

The programme, called The Female Orgasm, will examine attitudes and experiences of married couples aged between 25 and 106.

Mrs Roffey, of Byland Close, Eastbourne, said: "They asked me because I have a lot of stories and anecdotes about life.

"I got married when I was 18 and I have been with my husband, Vic, for 42 years.

"They did ask me some very personal questions but I could talk to the interviewer, Steve Humphries, for ages."

Mrs Roffey told him she had faked orgasms for the first six years of her marriage.

She said: "My husband never knew. I think it had something to do with my size.

"I was absolutely tiny and very self-conscious. It was the fashion to look like Marilyn Monroe back then."

Mrs Roffey has not told her six children about her impending television appearance and hopes none of them will see the documentary.

She said: "I don't think it's the sort of thing they would watch so I don't think they will find out. They'd be embarrassed."

Mrs Roffey, who has 12 grandchildren, has also appeared on television in Some Like It Hot, a documentary about holidays in Britain.

She said: "That came out last year. I loved doing that. It really took me back to when we went for holidays at the seaside."

She is already preparing for her next role, discussing alcoholism for another documentary.

Mrs Roffey said: "They said they were doing one on drink and I said I had number of stories about my dad. He was a nightmare."

The secret history of sex and marriage series was made for Channel 4 by Testimony Films.

Spokeswoman Roz Sinclair said: "Jo is an absolute hoot and one of our stars in the programme."

The series features intimate accounts from 1,000 men and women.

The show featuring Mrs Roffey will go out at 9pm next Tuesday.