'Stranger Things' David Harbour Oops!!! Was Season 3 Supposed to be a Secret?

8/17/2017 6:45 AM PDT

'Stranger Things' Star David Harbour Reveals Season 3

EXCLUSIVE

David Harbour, aka Chief Hopper on "Stranger Things," let a big cat out of the bag Wednesday when he accidentally talked about season 3.

We got Harbour at LAX Wednesday night when he talked about raging hormones on the set. The kids are getting older, and that leads to teenage craziness, especially when they enter season 3.

Hmmm ... was David supposed to mention a third season when season 2 doesn't premiere until October 27? Watch his reaction ... he tries to backpedal, but without much success.

BTW ... he seems like an awesome dude.