Shay Mitchell Streaks Topless Through Los Angeles -- And Shares the Video Proof

It was her assistant Sammy who reminded Shay, and her viewers, of a promise she'd made. "Do you remember in Morocco on our Shay-cation when you were like, 'Yeah, I'll run through the streets naked when I hit 3 million subscribers on YouTube," she told her. "It's a legally binding conversation."

Shay said she'd only do it if she could wear a mask that hides her identity, but Sammy was prepared for this, too. "I've been waiting my whole life for this," she said as she ran to a closet and got a full-head unicorn mask.

Sammy couldn't believe it as Shay slowly stripped down to a pair of panties with the words "Nice Buns" across her bottom and took off down the sidewalk. Sammy drove alongside her recording the morning jog, as she fearlessly jogged past people driving and walking. Everyone was stopping to take a look.

Finally, she got into Sammy's car. "A deal is a deal and I did it," she said breathlessly. "Guess what happens when I hit ten?"

Uh...no underwear?

Shay played Emily Fields on "Pretty Little Liars," which ended its run on TV last year, but she'll be back soon in "The Heiresses" -- another soap opera from "PLL" creator I. Marlene King.