Thanks for your comments...
I'm not going to rise to your bait, but what I will say is...
Your perspective is nothing that hasn't been expressed before, but what I will say is to remember that it takes two to tango and also that emotions are very powerful and very real things that only the 'eye of the beholder' can truly appreciate (for good or bad!).
I honestly held your perspective when a colleague was having an affair with a guy at a club we were at, and I was disgusted. But this situation just naturally happened gradually over time and just dawned on me what it was and we had both discussed what it was too.
People get a bit bored/restless in their current relationship and if someone provides an opportunity they will "fall in love" with that person. People are generally needy and fickle. If she does ever leave her husband for you then you should expect the same treatment a few years down the line.