This from Liz Riggs over at Mockingbird is excellent:
Infidelity has always permeated culture. From the dawn of time to modern television, “stepping out” has become a ubiquitous plot point in everything from classic novels to modern film. This is probably because it gnaws at the core of same very raw and visceral human emotions: love, lust, and, ultimately, the tipping point of all affairs: temptation.
As a society, these moments of betrayal have become a simple part of human life. They happen, people move on (or maybe they don’t), and then everyone talks about how “awful” and devastating” that was. And, yet, in popular culture viewers can find themselves subconsciously rooting for these affairs. It’s as though we want them to happen; we’re yearning for the moment where this act of infidelity finally comes to fruition and is able to satisfy our desire for easing the emotion/sexual/romantic tension.
For an issue that feels so black and white, what about this becomes so grey?
Riggs goes on to mention Mad Men as one example of a show where we find ourselves rooting for infidelity as we follow the story. I stopped watching the show after season four and this was a huge reason why. By season three, most everyone was pulling for Don and Betty to split because Don was so obviously unhappy and Betty was so obviously insane. And while Don wondered a bit in season four and hit rock bottom a couple times, by the end of the season his reward for splitting from his insane wife and suburban life was an equally attractive but completely sane wife who, as a bonus, got along great with his kids. Not only did the story encourage us to root for infidelity because of the way it portrayed the marriage of the protagonist, the lesson at the end of season four seemed to be “and it all worked out brilliantly too!”
(I should note, for sake of honesty, that from what I can gather season five and six actually call that reading into question quite a bit, but season four lost me so completely that I didn’t think it was worthwhile spending another 10-20 hours with the show to see if it changed course.)