The 70-year-old star was married to her first husband Tim Street-Porter for eight years between 1967 and 1975.
Speaking on the daytime panel show today about “What If” moments, Janet revealed all about how her first marriage ended.
She recalled: "I was married to my first husband for about six or seven years and I was having an affair and he tracked me down to this cottage in the New Forest.
"There was a knock on the door – luckily I had all my clothes on.
Loose Women star Janet Street Porter opened up about her infidelity
Loose Women star Stacey Solomon was shocked at Janet's dramatic revelation
There was my husband
Janet Street Porter
"And there was my husband."
As her co-stars Stacey Solomon and Anne Diamond gasped, Janet said that Tim was willing to forgive her if she came with him right away.
She continued: ”He told me, ’we'll drive to London and no more will be said about it.'
"I closed the door and said to my boyfriend: 'Why can't he give me 10 minutes?'"
Loose Women: Janet said her husband had been willing to forgive her
Loose Women confessions
Tue, November 1, 2016
The candid Loose Women panelist are always shocking us with their confessions. Here are some of the best revelations.
1 of 17
Linda Robson claimed that Joe Swash, Stacey Solomans's boyfriend, lost his virginity at her house
"I spent the whole three minutes arguing and the next minute I heard the car drive off."
Janet and Tim divorced after the incident in the New Forest and the newspaper columnist went on to get married and divorced a further three times.
She is currently in a long-term relationship with Peter Spanton, a former restaurateur.
Loose Women continues weekdays at 12.30pm on ITV.