The concept of “living in sin” could be dying a not-so-slow death. According to USA Today, a new study by the National Marriage Project has found that among Americans and our friends across the pond, cohabitation is growing more and more popular as an alternative to marriage. (From 1995-2005, the marriage rate in the U.S. declined nearly 20%.) Quoth one half of a cohabitating couple, “It’s what’s happening in the world of dating, and it’s not necessarily a path anywhere.”

For some couples, that works out just fine. They’re not interested in marriage, so the only path they need is the one toward their shared mailbox. But some experts — and, you know, people interested in a certain rose-strewn path toward a certain officiant — still wonder if living together is the most advisable next step. So, in certain cases, do certain superheroes.

What are your thoughts/experiences? Have you been shacked up — and back? Share!