Celebrity couples and the staying power of their various relationships are hot topics of conversation in the celebrity gossip world.
Some stars change spouses like regular people change their underpants, staying married for just a matter of days before calling it quits. Others maintain such high profiles we can't help but know they're together.
(Looking at you, Kim Kardashian and Kanye West.)
And then there are the celebrity couples who play it super smart. So smart, in fact, that we didn't even know they were together! They're rarely photographed in the same place at the same time, and they don't talk about their relationships with the media.
They know how to keep the private in the phrase "private life." (That doesn't always work, however, as the Gwyneth Paltrow and Chris Martin divorce proves...)
Occasionally, however, these couples step out in public together and leave the world going "wait, WHAT? They're MARRIED?"
Check out this list of 13 celebrity couples you didn't know were together! Which couple shocks you most?