Ashton Kutcher appeared on The Ellen DeGeneres Show Friday, where he might've accidentally revealed a major Two and a Half Men spoiler.While discussing the upcoming series finale of the long-running CBS sitcom, Ellen DeGeneres asked whether former star Charlie Sheen would return. Caught off guard, Kutcher's mouth gaped open, he flailed his arms and shook his head in silence. Eventually, he pulled himself together enough to say this: "If you're working on the Warner Bros. lot, if there's sirens, come save me.""So Charlie comes back," DeGeneres needled. "I didn't say that. Did I say that?" Kutcher said, giggling. "If you smell something, I wasn't smoking it" he added.Sheen was an original cast member of Two and a Half Men who starred on the show until 2011, when his off-screen behavior got him fired and his character Charlie Harper met a gruesome end. Kutcher was then brought on to fill his spot.The Two and a Half Men series finale airs Thursday, Feb. 19 at 8:30/7:30c. Do you want Sheen to return?