I mean, it is all about the happiness of the adults. Divorce, remarry, have b/f, g/f, live-ins, etc.
I'll go with Dr. Laura on this one: Abuse, Addiction or Adultary are the primary valid reasons for Divorce.
But "I'm not happy" or "I've fallen out of love" are just crap.
Shhh! If you're going to continue to speak such reasonable stuff you're going to be in trouble with some of the folks who post here.