I’ll never forget my first serious experience of negotiation.

I was selling my first house, a small, terraced house in a cheap part of the city. I loved it, because it was the first house I had owned, and because I had put a lot of work – and a lot of myself – into it. I had decorated every room; I had refitted the kitchen; I had installed central heating to replace electric storage heaters. I was moving to a new area, where I knew housing was going to be a lot more expensive.

I had received an offer to buy my house from a junior colleague at work. Obviously that made things slightly awkward to start with. But I was unprepared for what happened when he asked if he could visit again, with a family friend.

They duly arrived, and I showed them around. The family friend, an older gentleman, was very appreciative, admiring everything I had done, complimenting me on my workmanship, and so on. And then, at the end of the visit, he pitched me a new price, substantially lower than the offer my colleague had previously made. I was caught off guard. Having refused the new price, I felt I had to respond to his questions, starting with what was the lowest price I would accept? He came back with requests to throw in this and that if they agreed to a higher price, and so on. We eventually agreed a deal – which actually was not such a bad deal from my point of view – but I was left feeling bruised.

Looking back, I have to admire the technique. All the praise, all the efforts to make me feel good first, worked a treat, and there was nothing in the negotiation itself that I could criticise. He did a good job for my colleague. So why did I feel bruised?

The one thing that was missing in the exchange was creating an honest expectation. I had been led to believe that the friend was there to give a second opinion. It was my colleague’s first house purchase, just as it had been mine, so understandably he wanted someone else to endorse his judgement. I had not expected that the friend was there to negotiate on his behalf – after all, an offer had already been made. Perhaps I was a bit naïve, but I was caught unprepared; the negotiation had high financial and emotional value for me, and I had no experience of handling something like that. I felt that I was backed into a corner, and that personal trust had been breached.

So what is the lesson? Don’t just play fair – make sure everyone knows what game you are going to be playing beforehand, especially if personal relationships are involved. Trust is too important, and too hard to rebuild, to risk losing.