Michael Fassbender is an expert on celebrity penises. Don’t believe me? Check him out as he participates in a game of “Members Only,” a game in which he correctly identified the meat-and-potatoes of Harvey Keitel, Viggo Mortensen, and Watchmen‘s Dr. Manhattan (whose bright-blue member we thought was far too easy, by the way). The one celebrity schlong he couldn’t place, however, was Jason Segel’s — he must have missed its starring role in Forgetting Sarah Marshall, it would seem.