I can't speak to the evolutionary aspect, since I haven't studied that.
I don't think your feelings make you a bad man or a perv. It depends what you do about your feelings that will make you "bad" or "good." And that also depends on how we define bad and good in our culture, and why they are defined that way...
At the very least (and I am sure that there will be varying opinions on this) I think if you intend on acting on your feelings of love/lust for this other woman that you owe your wife some honesty, since she is the one you have made a public commitment to.
Female, age 51, 5' 9"
SW - 183 (Jan 22, 2012), CW - 159, GW - healthy.
Met my 2012 goals by losing 24 pounds.
2013 goals are to get fit and strong!