Ryan Reynolds' "Deadpool 2" opens in just a few weeks, and it will still have to fight "Avengers: Infinity War" for box office dominance.

That might be tougher than beating Thanos himself.

"Avengers 3" just had the biggest opening of all time, and it's not going to slow down soon. Reynolds showed he's a good sport about these things -- and still Deadpool at all times -- by sharing a congratulatory note to the "Avengers" team.

He cleverly lauded their success at his own expense, showing off a rejection letter from Tony Stark/Iron Man (Robert Downey Jr.):

Re: Joining the Avengers

No.

Absolutely not.

Go bother Prof X.

No.

Aww. But that letter is from 2012, man. Try again next year! (Gotta love the coffee mug stain and the other little details. We need that stationary.)

Fans replied on Professor Xavier's behalf:

Deadpool isn't quite in the Marvel universe yet, despite Disney's plan to acquire 21st Century Fox. Marvel Studios boss Kevin Feige said any kind of "X-Men"/"Avengers" crossover "would be years away."

You know what's not years away? "Deadpool 2." It opens in theaters May 18. The final trailer had a Thanos shout-out, since Josh Brolin plays both Thanos in the Marvel Cinematic Universe and Cable in "Deadpool 2."

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