@CoastalRat,
Dear Coastal rat, i will start off calm then might fly into a rage later on in my response....we will see.
In principle, it is not the best idea to have an affair with your mates wife. In fact with all of my mates bar one, i would not even consider it. It just so happens that one good friend has a wife who is my kryptonite. For many years i have admired her but never ever made an attempt to get her into bed. However that all went south when it became clear she was interested in me and once she put it out there, resistance was never going to happen.
At the end of the day pal, there are bigger issues in the world. Seriously, why do you GAF about what other people do.
So to the person who was battling with this question, just go with what you feel comfortable with.