Sometimes I think that I've got no right to feel bitter, but mostly I just feel angry.

Denise and I met at university and had a great connection. We're accountants, which doesn't sound exciting, but I'm in corporate venture transactions, where the financial rewards are very thrilling indeed and Denise is a partner in a large firm.

I'd never been faithful to Denise, even when first married, but I was always discreet. We had a major row when she decided she wanted a child and I didn't, but she talked me into it. Just four weeks later she was pregnant, which was when I first met Jane.

Jane was a high-flyer who was joining our division of the bank. Jane was absolutely stunning and within days we plunged into an affair which consumed us both. It started › what a cliché › after working late one night, while we were trying to grab taxis in the rain. We were both under her umbrella, laughing because I was so much taller than her that the rain was pouring straight down her neck, and then I kissed her.

Her response to my kiss was to pull me into an alleyway. It was dark and smelly but we tore at each other's clothes up against the grimy bricks, in a frenzy I'd never experienced before.

In the taxi afterwards we frantically sorted our clothes and parted at the station, where I tried to smarten myself up before getting the train home to Denise.

Denise was in bed and I sat up for hours. If Denise hadn't been pregnant I would have left then. Instead, that was the beginning of three years of ecstasy and agony, to use another cliché. Jane and I were totally professional in front of colleagues, but we took risks in other ways I still cannot believe.

Jane would make an appointment with me through my secretary, come in with a file, lock the door and take her skirt off. We frequently ate in a restaurant downstairs from our office which many of our colleagues used, but I doubt any of them also regularly had passionate encounters in the alleyway behind the restaurant. I lived in fear of getting caught as I would have been instantly sacked, but nothing could have stopped me.

The riskiest time was at a conference, when I went into a stationery cupboard off the main room and Jane followed me — despite knowing that if anyone opened the door we would be seen by nearly 200 people.

It wasn't just a physical thing, mind-blowing and addictive though that was. Jane was a challenge in every way, good at her job, fascinating to talk to and great fun, though always ready to stand her ground and fight.

I finally told her about Denise's pregnancy three months before the baby was born and she was furious › not just about the baby but because I had lied to her. She even punched me, but I almost enjoyed that, so besotted by her that any physical contact at all was exciting.

When Tom was born, I was in turmoil. Jane was obviously very hurt by my instant love for him, and Denise was starting to question the distance between us, so I felt very torn. Life was a constant juggle between my son, my work, and Jane — until she said she was no longer happy with just an affair, so she was applying for a transfer.

I couldn't bear the thought of losing her, so I promised I would leave Denise. The next few months were utter hell, as I left Denise, bought a flat and tried to organise seeing Tom as much as possible. Denise simply couldn't believe it. Although I said I'd only recently got together with Jane, she didn't believe me, finally asking if we'd started our affair while she was pregnant. I denied it, but I don't think she ever believed or forgave me and the next few years were punctuated with broken arrangements, cancellations and rows about access.

I was surprised when Jane said she wanted to get married as she'd always said marriage and children weren't on her agenda. I wasn't keen, but eventually agreed. The following year I was genuinely taken aback when Jane said she wanted a baby.

This time I was adamant that a baby wasn't part of our agreement but the arguments raged for months › alongside our still wild attraction to each other › until she eventually said she would leave me and have a child with someone else. So I agreed, and Sally was born three years ago. I love her as much as Tom and the two of them adore each other.

But Jane only has time and energy for everything else apart from us, which has reduced our love making to a desultory once or twice a week in bed with the lights out. No sexy underwear, no flirty games, no interest in being whisked away for a weekend and never, ever anything different or vaguely naughty. We still enjoy the children, work together, meet for lunch, have lovely holidays, but I look at this beautiful woman who has caused me as much pain as pleasure and I don't know her.

Life isn't all about attraction but it was a really big thing for us and now she just shrugs and vaguely says: "Oh I know it's me › I should give you more attention." So I seem really pathetic, begging for affection.

I feel so short-changed and full of fury that at times I hate Jane, but I can't bring myself to admit it or do anything about it. All that passion and excitement should be the only thing that could justify the pain we caused to Denise and Tom but in the end I've ended up back exactly where I started — in a mediocre marriage.

All names have been changed. Picture posed by models.

Your say: Have your say about this true confession below...