My thought is that opening up a monogamous relationship is like taking the first olive out of the jar-the rest come easy. I fully understand the electric jolt of a new relationship. Admittedly, even married people separate and divorce. Nonetheless, the more people involved any person’s life, the easier it is to jettison one person who becomes either boring or a burden of some kind (e.g., disabled and requiring care). Society has a vested interest in people supporting each other, and not to put the burden on the public treasury.