I'd have to agree with the Dr., but it of course applies to both sexes equally.
A spouse that emotionally or sexually spurns the other has provided an impetus for that person to go somewhere else.
I've seen men that treat their wives like garbage and nasty emasculating women that belittle their husbands with every action. I think it is obvious that those types of spouses bare a great deal of responsibility if their spouse looks elsewhere.
That does not justify cheating (there are more honest ways to confront the problem), but its a contributing factor. Often a large one.
This principle applies to many things. Its wrong to be slothful at work, but a demeaning dishonest boss can bear a lot of the blame for the employees taking every opportunity to stop working.
Well said, expands upon the point I was feebly attempting earlier.
Excellent comments.