Watching my beloved son as he plays happily in the back garden, I am overwhelmed with love. He looks over at me and smiles, and in this moment I am absolutely certain that all the pain I went though to have him – and all the pain I caused – was worth it. It may sound callous and selfish, but having an affair turned out to be the best thing I ever did.

If I hadn’t cheated, I would never have become a mother. Now, years later, what is clear to me is that I didn’t leave my ex-husband for my lover, I left him for my child. A decade ago, I walked out on Matt, my husband of 11 years, following a year-long affair with Robbie, the man who is now my second husband.

I’m not proud of what I did, but I am not ashamed either. In life, I do not hide the facts. Most people who know me realise there was some ‘overlap’ between my relationships; they need only do the maths.

My friends understand, and those who didn’t chose to banish themselves from my life. The only reason I am writing this article under a pseudonym, and have changed the identities of everyone involved, is both to respect my ex-husband’s privacy and to protect my son, now eight. I don’t want him to worry that people are judging me at the school gate.

Believe me, I know what people think of those who have affairs. Naively, I used to think the same. There’s an assumption that if you cheat on your spouse you are feckless, untrustworthy or oversexed, that you simply ‘can’t keep it in your pants’.

While .