In full "Not Now, We're on the Plane, You dumbass!" is a response to somebody saying or doing something prematurely, or when they aren't supposed to.
Can also be shortened to "Not Now, we're on the plane" or "We're on the plane, you dumbass!"
The phrase is derived from a line by Josh Duhamel's character in Transformers Revenge of the Fallen. His character was responding to another who had prematurely deployed his parachute while inside of a plane.
User A: So, to remove the virus follow Step 1, step 2, step 3, then step 4. But ignore step 3 if you are running on Windows Vista.
User B: So I finished Step 1 and 2, skipped 3 and went to 4.
User A: Are you using Vista?
User B: No.
User A: Well don't do step 4! We're on the plane, you dumbass!
Inside Joke and you're on the Outside. Used on someone looking for an explanation of an inside joke. Usually leads to further confusion, as it is often use as an inside joke of its own.
Guy: Jane sure is bootylicious.
Guy 2: That thing is like a watermelon!
Girl: What are you guys talking about?
Guy: I J and you're on the O.
One of Jeffree Star's lipsticks based on his video with Shane Dawson and Ryland Adams . When they got kicked out of Walmart the security guard kept saying it even in the parking lot.
"You're still on the property I'm going to have to ask you to leave."
"But we're in the parking lot."
"It's still on our property."
"What's not your property? Olive Garden?!"