She told the paper: "I've never said I'm a saint and I feel hypocritical in a really big way but no one has an affair if they are entirely happy. I fully deserved it.
"If confronted, I'd have admitted it was all completely accurate. But I'd do it all again. I think everything happens for a reason and I think this man was brought into my life to teach me what love is."
Rebecca Jane founded her agency after she suspected her first husband of cheating on her while she was pregnant with their baby in 2006 but was left disheartened when no male investigators would "take her seriously".
So the property developer from Manchester took matters into her own hands, recruiting a group of friends to carry out surveillance on her suspect spouse, tracking him to a pub and sitting outside in a car watching him through binoculars.
Rebecca and a friend formed The Lady Detective Agency in 2009, and now the firm has operations in Manchester, London and Stockholm.
Rebecca also found the time to remarry in 2012 - and produced another baby, Peaches, a sister to Paris.
However, she ended up falling for her neighbour in 2013 and the pair spent months sneaking off to country hotels for secret trysts, both telling their respective partners they were working away.
Her lover cancelled his own wedding and Rebecca divorced her husband in 2015; he has since found a new love.
Despite their passionate affair, Rebecca's relationship with her neighbour didn't work out and they broke up last year. While he has gone on to find a new girlfriend, Rebecca is single.
THE LADY DETECTIVE AGENCY
Speaking about the cynical, distrustful nature of her job, Rebecca says: "I would love to live in a world in which people talked to each other, told the truth and I was out of a job.
"But unfortunately that's not realistic. It's sad but true.
"People lie and deny things, and when your partner keeps telling you you're wrong about your accusations it makes you feel as though you're going insane.
"People just want the truth, and to know that they aren't mad and imagining things. It's sad to find out your husband is cheating on you, but it's also a relief to know the truth."
Rebecca's first case involved a woman named Jane who was convinced her husband was having an affair.
"I wasn't convinced, and was amazed how quickly I turned into one of those judgmental people I was trying so hard not to be. When we discovered that he was in fact having an affair, I questioned whether I was doing the right thing by becoming a private investigator. But it was definitely my most rewarding case, and I never judge people who come to anymore."
Her trickiest case involved a gentleman desperate to trace his missing pet.
"His wife had run off with another man, all his money and their pet ferret. But all he wanted back was the ferret. It was the case that broke us, though - we never found the ferret. I felt really angry with myself, but there was no way round it. Sometimes there are just too many brick walls."
Her most bizarre case came about when a gay man asked the agency to trace a former partner who had absconded with some money.
"None of our cases are very funny but this was definitely the craziest. When we finally found the partner it turned he'd become a woman. He was a very convincing transsexual but as soon as we opened the door we knew it was him. That was a crackers case."
Occasionally her cases involve cheating celebrities - frequently footballers - and every now and then Rebecca is offered a job she won't take for fear of her safety.
"I was offered a case in Saudi Arabia but I don't want to do anything that would be dodgy or dangerous - I have to think about my family."
Rebecca has written a book, The Real Lady Detective Agency, detailing her route to becoming a private investigator and telling a collection of stories about cases she has worked on.
"The difference between us and other private detective agencies is that we care. I know there are some caring male investigators out there, but clients come to us because they know we're going to listen and we're not going to rip them off.
"I just want to create a place filled with people who I would have liked to talk to when my first husband was cheating on me."
