For Stephanie Endicott and Marcus Smallegan, first-year students at George Washington University, announcing to the world on Facebook that they had found love in a college dorm was a no-brainer. “It was important for me to share this with my friends since I’m so far away,” says Endicott, who’s 3,000 miles from her home in Maple Valley, Washington. Her new boyfriend is happy, since the last relationship he posted on Facebook ended with his girlfriend moving out of state and breaking up with him via a text message on his cell phone.

Often new relationships fall apart when the subject of linking couples on Facebook comes up—an option that requires the consent of both parties. But when it’s full speed ahead, the “couple” status on Facebook carries an air of solidity and permanence. “For those in a relationship, the theme that kept echoing was that Facebook made it official,” said Nicole Ellison, an assistant professor of telecommunication and information studies at Michigan State University who has studied social networking sites. “That was the term they used. And when the relationship fell apart, when you broke up on Facebook, that’s when the breakup was official.”

Facebook even produces a little red broken heart icon when a couple splits up. And if Facebook can certify relationships, it can also destroy them. Ellison learned of one young couple in a “Facebook-worthy” relationship in which the guy cheated on his girlfriend—who found out when the “other woman” looked up his Facebook profile, saw he was taken, and contacted her. “Then the two of them were in cahoots to make this guy’s life miserable,” Ellison said. “So if you are in a relationship, and it’s listed on Facebook, don’t cheat.”