Lauren Conrad needed plenty of Kleenex during her Hills adventure — but no crying moment is more popular than that unforgettable argument with Audrina when a single black tear rolled down her face. But, turns out, we've been wrong all these years about those makeup-infused, salty drops. SAY WHAT????

"I don’t think it was the mascara — I think it was the eyeliner that was running," the lovable Laguna Beach lady — who is returning to the network for the tenth-anniversary special The Hills: That Was Then, This is Now — told MTV News about that dramatic scene with her erstwhile roommate. "I still wear the same mascara, and it doesn’t run like that."

There we have it — the truth!! It wasn't the eyelash darkener/extender; it was that cosmetic responsible for her trademark cat-eye. Case closed on this mystery.

But back to these types of sad incidents loyalists saw all too often on the program: Lauren admitted it was "very normal" for her to get emotional during these types of situations but now, times are different.

"I rarely cry these days," she reflected.

What do you think about Lauren's revelation about those infamous mascara eyeliner tears? Sound off in the comments, and be sure to catch an all-day marathon kicking off on Tuesday morning at 10 a.m. featuring classic Hills episodes with some of your favorite cast members revealing "100 Things About 'The Hills'" — and then watch Lauren on The Hills: That Was Then, This is Now at 9/8c!