Most human communication is based on lies. Nevertheless, most of these lies are the ones we give each other permission to tell. I ask whether you like my garish new jacket, and the very question gives you permission awkwardly to stumble through a litany of disingenuous compliments. There is little wrong with socially sanctioned exaggerations and omissions. They are part of the glue of human communication and go a long way towards ensuring we don’t spend most of our time hating each other. It is OK to lie to each other in this way. But when you start lying to someone about lying to them, it’s time to reconsider whether what you’re doing is right.

For the last few months of our relationship, you had an affair. When I asked about it, you became indignant and denied it. You told me I should seek therapy and implied that I must be mentally ill, causing me to doubt my own perceptions.

You reassured me continually that you loved only me and no one else. Then you would throw contradictions at me, become uncommunicative and cold; you misdirected me by claiming our problems were unconnected to your secret new, ambiguous relationship with someone else.

It took a moment of weakness, a violation of privacy and the reading of texts meant for someone else to reveal that this was not the whole truth. That moment was one of extreme relief for me. It confirmed that I was not mentally ill, as your words had begun to convince me I was.

It is horrible to be torn between believing your partner and your own perceptions. I carried an almost constant sense of guilt, because I was unable to convince myself that you were telling me the truth.

When the truth came out, our relationship fell apart very quickly. I knew you had had affairs when you’d been with other partners, but naively believed that with me it would be different.

The real tragedy is that it has made it almost impossible to miss you. And that is sad because, aside from this, you really do deserve to be missed.

I hope that you treat your future partners with more honesty. Some things are hard to say, but I think you will be surprised by what people can accept hearing – if they feel they are being treated with respect and integrity.

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