Holly Willoughby and Phillip Schofield struggled to hold back giggles after renowned erotic writer Jilly Cooper invited them to an old-fashioned “feather party”.

The ITV This Morning presenters said they would even supply the feather when Jilly suggested she may bring back the tradition for her 80th birthday party this week.

“You have an enormous counterpane with a feather at the centre,” the author explained.

“Everybody shakes the counterpane and whoever the feather goes nearest has to remove a garment – like strip poker.”

Jilly appeared on the show on Thursday to talk about her latest book, Mount.

Speaking about her 50-year career as a novelist, which includes hit racy reads Riders and Rivals, she said she began as an “unholy terror” at school in Salisbury.

“All we thought about was men,” she said, “but there weren’t any, as it was all girls.

“They made sure all the gardeners were at least 80, so we wouldn’t lust after them.”

When she began finding success as an author, she said her own bank manager described her books as “disgusting” and asked: “How does Jilly know things like that?”

Holly and Phillip described Jilly as their favourite guest on the show and wished her a happy birthday – with or without the feather party.