After almost ten years and six children together, Angelina Jolie and Brad Pitt decided to tie the knot and get married. This isn't just a Hollywood love story. It represents broader cultural trends. More and more, the major milestones of a relationship are occurring prior to marriage rather than after.

But does this trend even matter? Does it matter if people have sex before marriage? A recent study (2014) at the University of Virginia rejects what they call "The Vegas Fallacy"—the idea that what happens in Vegas stays in Vegas, or that what happens before marriage doesn't effect our marriage today. The study reports:

Actually, what people do before marriage appears to matter. Specifically, how they conduct their romantic lives before they tie the knot is linked to their odds of having happy marriages. Consider sex. The vast majority of Americans—about 90 percent—have sex before marriage (Finer, 2007). Many of them have sex with multiple partners before finding the person they will eventually marry …

The ghosts of the prior romances can haunt new ones. Those who had more romantic experiences … are more likely to have lower-quality marriages than those with a less complicated romantic history … This doesn't mean that sex before marriage will doom a marriage, but sex with many different partners may be risky if you're looking for a high-quality marriage.