Where to begin?

Thats difficult. I cant point at a calendar and say "that was the day it all started". I suppose some background needs to be filled in before the story can commence.
I was married at the tender age of 19. A child bride, snatched from the cradle etc,etc. My wifes a year or so older than me. We had been courting (you dont often here that word nowadays) for about four years. Neither of us had much sexual experience. In my naivety, I was under the impression that all men had a high sex drive whereas women's were much lower. Most men, especially married men i spoke to said the same. As a result I suppose I regarded my sexual frustration as just one of those things.
I was never a ladies man. I always felt shy and awkward in the company of girls and had no more idea of how to chat a girl up than i had of how to perform brain surgery. I never really felt that girls found me attractive. I used to see mates looking trendy and suave, chatting up girls in the pub or disco and think "How do they do it?". I certainly never had a girl chat me up. In my dreams!
So I married at an early age, thanking my lucky stars that this pretty girl wanted to spend her life with me. Theres absolutely no doubt that i loved her dearly and would do anything for her and we shared the usual trials and tribulations that most couples go through. The financial worries, the joy of two sons of whom i am so proud, the arguments, the making up, the pets, the in-laws. Somehow we managed to keep it together through a mixture of love, mutual respect, doggedness and the fact that we both feared the unknown territory of being apart.
Then there was the sex or the lack of it. She never had a very high libido. I would say that on average we would make love two or three times a month. There were a couple of times when, for a few weeks or months, she would want sex every day. Then her hormones would settle back into their normal routine and that would be it for a few more years. With the low libido came a lack of adventure. She refused to wear sexy lingerie throughout her marriage, saying it made her feel self concious and we rarely ever made love with the light on. Yet she was an attractive girl with a good figure for a good many years. Time doesnt do any of us any favours but she is far from being an old frump even now.
I put up with it all those years. I never slept with another woman. Having said that, I dont ever remember getting the chance to. I didnt really go out anywhere without her. I rarely went for a lads night out. Perhaps given the opportunity i would have slept with dozens of women but i didnt so its pure conjecture.
I suppose, inevitably, it was the internet that changed things. It became possible to talk and flirt and share ones thoughts with women from all over the world without even getting out of your swivel chair.
The other major factor was starting my own business. This allowed me more freedom during the day to do as and go where i wish. Not that this had any bearing on my starting the business in the first place. I had never so much as been in a chatroom at that time so there was no ulterior motive or hidden agenda there. As time passed, however, I did start joining chatrooms, then dating sites etc with the knowledge that if the opportunity arose, I could get away from work without too much trouble.
And so it began. It was a slow progression but eventually i found myself deliberately looking for an illicit affair.

Ok. Thats the groundwork done. The interesting stuff is yet to come. Thanks for your patience but i feel that background is crucial to my story.