Oprah Winfrey often pretends to recognise famous people who say hello to her.

The 66-year-old media mogul admitted she frequently comes into contact with stars that she can't remember meeting in the past so has to fake a greeting.

Asked if she's ever pretended to know a celebrity when she in fact didn't, she admitted: ''I do it all the time. I don't know anybody. I'm walking through the crowds like, 'Hey! How you doing?' ''

Her friend Gayle King added: ''We'll say, 'She's been on your show before, he's been on your show before.' ''

The two friends were playing a game of 'Never Have I Ever' for OprahMag.com's series 'The OG Chronicles' and guest host Ashley Graham left Oprah baffled with her first question when she asked if either of them had ever stalked someone on Instagram.

The 'Wrinkle in Time' star said: ''I don't even know what that is.''

Ashley explained: ''You go to their page and look through every single photo and what their caption is, who's commenting.''

Oprah exclaimed: ''What are you doing that for? No.''

Oprah also confessed to having interviewed someone she disliked but neither she nor Gayle had ever sexted and were stunned when Ashley admitted she had exchanged raunchy texts and pictures with her husband Justin Ervin.

Oprah said: ''Hell no, are you kidding me? You never know where that picture's gonna end up.''

Both women had to put one of the fingers from their raised hands down when they admitted they had had one-night stands in 1982 and had considered cosmetic surgery, while Gayle got the giggles when asked if she'd ever lied to her best friend about her whereabouts.

Oprah said of her pal: ''That's a good story.''

Gayle declined to give details and simply said: ''I'm just gonna put my finger down.''

Oprah said: ''You should put two fingers down.''

Neither woman has ever been to a strip club and only Gayle had been skinny-dipping.

However, she asked: ''Does a hot tub count as a skinny-dipping?''

Oprah said: ''I've never skinny-dipped and I've got three pools at home.''

The pair have never been to a strip club or pole danced, but the question gave Oprah an idea.

She told Gayle: ''This birthday I'm gonna get you a pole, girl. For the woman who has everything.''

Her friend replied: ''Does it come with a man? If it comes with a man then do that.''