When you work on a show like Stranger Things where secrecy is key, you've got to be very careful what you say. The cast has been good about keeping things secret for the most part, but occasionally someone will slip up and say something they definitely should not have. But which cast member spills the beans most often? TV Guide went straight to the source to find out!

"David Harbour is the worst at spilling things," Millie Bobby Brown revealed without hesitation. "He always does it."

Charlie Heaton also picked Harbour as their biggest leaker, but newcomer Sadie Sink picked someone we never would have guessed: executive producer Shawn Levy. Dang, girl, you've got to be brave to call out your boss when he's standing right next to you!

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"I'm definitely the worst," Levy admitted, though he did call out one other cast member as a secret spoiler operative. "I feel like the kids will send Noah [Schnapp] to get info out of me and then he'll run and share it with all the other kids in the cast, so I think Noah might be our leak."

Stranger Things' first two seasons are available to stream on Netflix. Season 3 is expected to debut in 2019.