"She was doing my mom's makeup on this TV movie, and I went down to visit. It was in Florida. I met Sheryl, and I was like immediately obsessed with her.
"First of all, she was dating Keanu Reeves, who was my celebrity crush. And she was so cool.
"And she knew that I was sneaking cigarettes, and she would come smoke with me behind the trailer, and she taught me how to give a blow job, and you know, all the classic Sheryl stuff."
The 'Politician' actress - who has children Apple, 16, and 14-year-old Moses with ex-husband Chris Martin and is now married to Brad Falchuk - didn't share the specifics of Sheryl's tips but praised her for being so open about sexual matters because they weren't conversations she was used to having.
She said: "It was less about remembering the technique -- although I'm sure that I implemented it the first chance I got.
"It was so cool to have someone treat me like an adult and see me as like a young woman and someone who is sexual. She just made me feel so free,"
Gwyneth, 47, admitted she "worshipped" Sheryl because she was so "awesome".
She gushed: "I just worshipped her. I thought she was literally the coolest chick of all time.
"She was so awesome to me. And I was a high school kid. Like, the fact that she's loved me that much before I was anyone or anything, you know?"
