If you need an Avengers secret kept, maybe don't call Mark Ruffalo. The 50-year-old actor stopped by The Tonight Show Starring Jimmy Fallon on Oct. 5 and talked all things Marvel, from his cast members' matching tattoos to the upcoming installment in the thrilling action series.
Within the Marvel Cinematic Universe, Ruffalo's known for being slightly loose-lipped — just ask his costar Don Cheadle. Right under our noses, Ruffalo accidentally revealed the ending for Avengers: Infinity War while doing press last year, and during his interview with Fallon, he (jokingly) spilled some more. While it seems pretty darn unbelievable that Ruffalo would make the same mistake twice, only the Tonight Show audience knows for sure. Watch the video above to see what Ruffalo had to say about Avengers 4, then keep reading to see how he tried to backtrack and how it eventually got him "fired." Something tells us, he'll be all right.