Because of EVERYTHING. 20 years of very little effort at meeting my primary needs is quite enough, even WITHOUT the affair, don't you think?
And "JUST" the affair would also be enough.
But combined????
Throw in the fact that I just don't know who she is anymore, this woman who sits around watching plastic surgery shows as "The Cougar" on TV, coloring her every every four days, and you have a man who's reached the end of what was once his very long rope.