I had been with my boyfriend for three years — living with him for two — when I found out he'd been lying about his age. I was looking for batteries in his desk when I came across an expired passport; the photo was so cute that I almost didn't notice the date of birth was off. Then I noticed. I checked my math. Yep. Definitely off.

"It was a misprint," he told me later when I asked him about it. "That's why I don't use that passport anymore."

"You don't use it anymore because it's expired," I pointed out. I asked to see his driver's license.

"I… lost it," he said. The jig was up.

We'd been set up on a blind date years earlier, just before my twenty-third birthday. He was about eight years older, according to his social media profile. It wasn't the hugest age gap, but it was big enough to notice, especially since I was fresh out of college. On our first date, I think I might have said something like, "Lucky thing it's only eight years — nine would be a dealbreaker."

If he registered any discomfort at that, I didn't notice. Before too long, I'd moved in. Later, when I found out from that expired passport that he was a year older than he'd claimed, it was hard to decide how much I was supposed to care.

He told me it had all started with an vanity-inspired decision to shave off a year when he'd filled out his profile, and that once he'd started lying, he couldn't figure out how to stop. I got it, kind of, and anyway, a year seemed fairly insignificant. But we'd celebrated his birthdays together: thirty-two, thirty-three, thirty-four. His lie had been small — even funny from a certain angle — but one tiny lie had led to more lies, and then to bigger ones.

We laughed about the truth when it came out, and stayed together for several more birthdays after that — thirty-six, thirty-seven, thirty-eight, never mentioning phantom thirty-five — but things started to go downhill. I began to wonder what other secrets and not-quite-truths were buried under the junk in the desk drawer. Sometimes I found myself rolling over in bed in the middle of the night and looking at his face, wondering how well I knew him.

Of course, I had my own secrets. Everyone does. Maybe that was what really made me nervous.

But let's face it: the secrets my ex and I were keeping from each other were nothing compared to some people's. In The Honorable Woman, a new miniseries on SundanceTV, Maggie Gyllenhaal plays a billionaire baroness with secrets. When those skeletons threaten to come busting out, she's forced to question everything she cares about.

While your secrets might not rise to the level of state security any more than mine did, the personal costs of even minor cover-ups can still be serious. Even with the best intentions — why tell your girlfriend you're getting that drink with your ex just to get her all upset over nothing? — secrets often start to fester before you know it.

Were you well into your thirties when you discovered your mom had a secret life as a CIA agent? Have you struggled over whether to spill the beans after spotting a friend's partner in public with a suspicious stranger? Whether it's at home or at work, how far have you (or someone you know) gone to protect a secret from coming to light? Share your own tales of cover-ups and consequences in the comments. And if you're still operating from the shadows, you can always use a Kinja burner account to be double-sure your identity remains hidden. With that secret off your chest, you'll feel a little less burdened when you sit down to watch The Honorable Woman on SundanceTV tonight at 10 PM ET.

The author is a writer somewhere in New York.

This post is a sponsored collaboration between SundanceTV and Studio@Gawker.