i would love to get your take on this topic. I think social media, reality tv and the celebrity world in general has changed how relationships are viewed.  Cheating has become the "cool" thing to do.
 
Temptation seems to be one of the big adversaries of staying faithful. If there wasn't a notion (temptation) to cheat, more people would be faithful. We all are tempted! How you face the temptation will determine the outcome. What works well for me is avoiding situations that leave me vulnerable. You have to know your limitations. Some people are stronger and are able to handle more. First things first, realize what your weak points are. Second is to avoid those compromising situations. Some people, myself included, can handle flirting and some can't. Some can handle being alone with someone they share a mutual attraction with, I can't (my limitation). What helps you remain faithful?