A little piece I forgot to add: one of the worst parts of this deal with my wife's boyfriend and her not being "in love" with me is that is absolutely has caused me to love my wife less. I could handle the idea of her loving others, but being more "in love" with others, well that doesn't fly with me.
I was kind of excited by the prospect of going out and getting myself a girlfriend on the side as well, but it was more as a fun thing to toss into a fullfilled relationship. Now, this has caused me to feel there is a hole in my relationship that I want another girl to help fill in.
Also, it's worth noting, I was sold on this by my wife telling me exactly what I'm saying; the relationship was as good or better than ever and this was the peak of Maslow's Hierarchy of Needs. Seems that wasn't the case.