'251: Welcome to the Intimate Life of Annabel Chong' opened to a full house on Thursday, and all 14 performances of the 90-minute play are already sold out.

"I thought it was a progressive step in stage performance in Singapore. I think that anything that involves pushing boundaries is progress in Singapore," a 28-year-old managing consultant said after the premiere. "I think it was a subject that was often shoved under the carpet and it deserved some time in the light," he said.

Annabel Chong — whose real name is Grace Quek — once had sex 251 times with 70 men in less than 10 hours, a marathon session chronicled in the 1995 US film 'The World's Biggest Gang Bang'.

'251' explains how Quek, an energetic teenager and devoted daughter of Christian parents, transformed into a porn legend and a broken woman. The play — interspersed with social commentaries and monologue — explores the turning points in Quek's life, including a gang rape which she says took place in London.

Loretta Chen, the director, said that the play — rated for audiences above 18 years of age — would have been banned only a few years ago. Authorities still had concerns about '251' and gave Chen a list of guidelines to follow. Full nudity and group sex could not be depicted, but a topless scene was allowed.

In one scene, a character known as Mr Big threatens to "tame" Chong as the couple simulates different sexual positions, in what was seen as a jibe at the government's attempts to keep its citizens on a tight leash.

21-year-old student Fiona Huang said "They nailed what Singapore was like together with the sex positions. It was kind of an interesting take and I thought it was really funny,"