The former ‘Strictly Come Dancing’ contestant regaled the audience with his tale about an incident that took place when he was in his twenties, while he was on tour with Bobby Brown.
Peter and Craig Revel-Horwood joined the panel
He told the panel: "I thought he[Bobby] really liked me because he kept asking me to come out in the evenings with him.
"I thought wow this guy is so nice. And every time he invited me, he would say 'Bring your girlfriend along too'. I thought he was the nicest guy.
“So one night, we all went out - but she didn't come home with me. In fact she didn't come back to our room until 10am the next day.
"When she came through the door, I said 'How's Bobby?' She didn't even deny what had happened. She just said 'Well it is Bobby Brown!'
"I was like, 'Right get out, your stuff is packed up in the hall.' And then afterwards, I decided to make a visit to her sister's house - who was really nice.
"I got there and we were... talking about our problems. She was a shoulder to cry on and she looked after me."
A shoulder to cry on, eh? Andrea McLean wasn’t completely satisfied with this explanation and asked Peter if he had sex with his partner’s sister.
"I did not say that," he laughed. "But yes I did. It eased the pain. And I was young and foolish!"
Friday’s ‘Loose Women’ was the first in a series of ‘Loose Women And Men’ shows, which feature a panel made up of blokes and the usual female panelists.
Peter was supported by his wife Emily MacDonagh, who was in the front row for the duration of the show.
Watch Peter make his confession in the video above…