The Formula 1 paddock is no stranger to controversy and rifts, but the recent war of words between Red Bull and McLaren's Lando Norris is perhaps the first disagreement to play out via paper airplanes.
It all started following qualifying for the Portuguese Grand Prix. Marko seemed to suggest that Norris had deliberately blocked Max Verstappen on the Dutchman's crucial flying lap, with the Red Bull advisor implying that this was influenced by McLaren's engine supplier being Mercedes.
"Norris was told in the second run to not do Max a favour, the Mercedes team is very sporting," Marko told ServusTv, seemingly a sarcastic reference to McLaren's use of Mercedes engine power.
Later Norris laughed off the comments, whilst McLaren's team principal Andreas Seidl made it clear that his team are thinking about themselves in qualifying and not anybody else.
"First of all, just to be clear, we drive for ourselves, not for anyone else," Seidl told select members of the media, including RacingNews365.com.
Whilst this played out in the press, it has now come to light that the war of words was also continuing in the paddock in an unusual manner.
Norris received a paper airplane from a passer-by - presumably from the Red Bull family - which, when opened, contained the message: "Don't get in our way again!"
In the latest McLaren Unboxed video, the Briton is seen taking his revenge by sending a note back, starting with the words: "Don't start the lap so close..."
After completing the message, Norris posted the airplane back into the Red Bull garage. Maybe a response will be sent at this weekend's Spanish Grand Prix?
Watch the video below to see it all unfold: