Robert Downey Jr. may have just spoiled Thunderbolts and fans aren't happy

Spoilers for the Thunderbolts ending and Thunderbolts post-credits scene follow.

Robert Downey Jr. might be going method for Avengers: Doomsday after breaking the cardinal rule of spoiling Thunderbolts before its opening weekend was even over. Taking to Instagram to praise the latest chapter in the MCU, the man who will return to the franchise as Doctor Doom said, "Just wow!!! Dinner and a show with the Old Avengers. So cool, fresh, and deep. Big congrats." Unfortunately, some fans picked up on the "Old Avengers" comment and quickly put the pieces together, finally realizing what the asterisk meant after all this time, before seeing it for themselves in theaters.

The man who will be Doom was referring to the film's finale that sees Yelena (Florence Pugh) and her new friends rebranded as the New Avengers, much to the frustration of Sam Wilson (Anthony Mackie), who is taking the team to court for stealing the name of Earth's Mightiest Heroes. From here, the replies came thick and fast in response to the star's post. "Did RDJ just spoiler thunderbolts for me," one fan said. "I shouldn’t have read into the caption." Another added, "Bro casually gave Thunderbolts* spoiler in caption," and one fan joked, "His villain arc is really already starting."

While some fans might have been a little wound up over RDJ taking the title of new Spoiler Supreme, others were interested in who was in attendance for the private showing of the film. The post revealed that Chris Hemsworth, Channing Tatum, Simu Liu, Paul Rudd, Ebon Moss Bachrach, Vanessa Kirby, Winston Duke, and Anthony Mackie were all present, giving us at least a rough idea of just how much of the cast from the initial announcement is already hard at work for the upcoming mega-MCU event movie.

But while a handful of heroes, one new villain, and a bunch of iconic X-Men are set to appear, Kevin Feige has promised that there are still more cast members to join the project. We'll have to see who has made the cut when Avengers: Doomsday arrives in theaters on May 1, 2026. If you want to check out every other upcoming movie and show making its way into the MCU, check out our complete list here.