The woman, now aged 20, claims that when she was 16 she was driven to 62-year-old Mr Oyston's country mansion, where she watched him have sex with another girl before being ordered to take her clothes off and join them.
Cross-examined by Anthony Scrivener QC, defending, at Liverpool Crown Court, the woman admitted she had smoked cannabis and taken ecstasy and amphetamines occasionally since she was 13.
She said she smoked cannabis as recently as last year. "I was smoking cannabis to forget," she said. "It made me forget things. I didn't want to face up to things."
But she told Mr Scrivener: "It doesn't give him the right to do what he did though, does it?"
Mr Scrivener replied: "Not at all, not at all."
The woman also claims Mr Oyston, chairman of Blackpool football club, forced her to perform oral sex in the back of a car.
Mr Oyston, of Claughton Hall, near Lancaster, pleads not guilty to raping and indecently assaulting the woman, and denies raping another woman.
The first woman in the case, who has already given evidence, has told the jury she was driven to Mr Oyston's house late at night and raped on the four-poster bed.
Asked by Mr Scrivener whether she protested when Mr Oyston allegedly forced her to have oral sex, the woman asked: "What could I do?"
Mr Scrivener said: "You could have said no."
"I put my head up and he pulled it back down," the woman said.
She refuted Mr Scrivener's suggestion that the incident never took place. Mr Scrivener said she could have asked Lisa French, who was sitting in the front seat of the car, for help.
The woman said: "Lisa ... she was going out with him."
She denied she had been interested in looking around Mr Oyston's house.
Mr Scrivener suggested that she was, and that she went upstairs to look at the bedroom. Lisa French had gone to the bathroom and when she came out they had all left.
The woman said: "You can suggest what you like but I am not lying. I know what happened."
She could not remember if she saw a doctor after the incident.
Asked why she had not complained to anyone, she said: "I was too ashamed."Reuse content