Much like Deadpool enjoyed breaking down the fourth wall in his movie, he continues to chip away at the divide between Fox and Disney’s Marvel Cinematic Universe. Ryan Reynolds, who plays the titular hero in the R-rated superhero franchise, took to Twitter to congratulate Avengers: Infinity War on its wildly successful opening weekend with a very curt letter to the Merc with a Mouth from Tony Stark (a.k.a. Iron Man) of Stark Enterprises.

“From a guy who never knows when to quit, I’m glad you guys never did. Congrats #Avengers,” tweeted Reynolds with a photo of a rejection letter from Stark to Deadpool in regards to joining the Avengers.

The letter from Stark doesn’t mince words telling Deadpool that he is not welcome to join the Avengers. “Go bother Prof. X,” Stark says.

Pending Fox and Disney merger aside, Deadpool is already part of the X-universe (he addresses that in his own tongue-in-cheek way in the first Deadpool). Even so, this isn’t the first time Reynolds dipped his foot in the Disney pool using Deadpool. He zinged the merger at CinemaCon and posted a trolling Deadpool-style tweet about the Matterhorn shortly after the news of the Disney-Fox merger this year (see below). And in a trailer for Deadpool 2 there are some subtle nods to Pixar with a Deadpool action figure dressed as Woody from Toy Story and a raunchy Infinity Stones reference when they introduce the character of Cable played by Josh Brolin — who also plays MCU’s Infinity Gauntlet-wearing purple baddie Thanos.

Avengers: Infinity War opened to $250M, which beats out Star Wars: The Force Awakens ($247.96M). Reynolds’ Deadpool 2 is also looking to make an impact on the box office when it opens May 18.