A few days after the title for Avengers 4 appears to have leaked, actor Mark Ruffalo teamed up with late night host Jimmy Fallon to poke fun at the secrecy of the title, which Marvel Studios still hasn't confirmed.It all started with a single tweet from Ruffalo yesterday after the taping of Friday's Tonight Show with Jimmy Fallon. Ruffalo, who like his fellow Marvel co-star Tom Holland, is known for spoilers, sent a tweet "begging" Fallon to bleep out the "spoiler" he let slip out during filming. To which Fallon responded, "Dude, it’s too late - already sent the final show to Burbank for air. Are you sure you’re gonna be in trouble? We could maybe bleep it out."RELATED: The Russo Bros. May Have Given Away Avengers 4’s Final Title

It's not entirely clear what Ruffalo said. However, it was obviously a joke. The biggest takeaway from the joke, of course, was that Ruffalo said that the title for Avengers 4 was "already out there." This, naturally, has led many to believe the actor confirmed the title Avengers: Annihilation.

The Russo Brothers then responded to Ruffalo's tweet at Fallon, joking that he was fired for the spoiler.

While it's more than likely not what Marvel fans had been hoping for, the teasing did help bring more awareness to the reason the actor was actually visiting the show. Rather than appearing to promote an upcoming project, Ruffalo was in attendance to promote the My First Time campaign, which helps to register young people to vote. Just last week, the campaign unveiled a video which featured a handful of Avengers actors, including the likes of Chadwick Boseman, Chris Evans, Scarlett Johansson, Don Cheadle, and of course, Ruffalo, himself.

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Ruffalo will next be seen as Bruce Banner in Avengers 4. The film, which hails from directors Joe and Anthony Russo, also stars Robert Downey Jr., Chris Evans, Chris Hemsworth, Brie Larson, Mark Ruffalo, Jeremy Renner, Scarlett Johansson, Paul Bettany, Anthony Mackie, Paul Rudd, Elizabeth Olsen, Tom Holland, Benedict Cumberbatch, Chadwick Boseman, Chris Pratt, Zoe Saldana, Dave Bautista, Bradley Cooper, Vin Diesel, Karen Gillan, Evangeline Lilly and Josh Brolin. The film is set to hit theaters on May 3, 2019.