1. unfaithfulness in marriage or relationship caused by the act of wife bringing home ass for the husband / boyfriend; threesomes, orgies. 2. belief of person or persons that marriage is not monogamous, boring or repetative.
My girl picked up a chick at the mall, brought her home and we had a threesome! That's Pornfidelity!
There is a website for an example. Wish your girl had that mindstate?