Dinner for Schmucks (2010)

Takes one to know one.

Rising executive Tim Conrad works for a boss who hosts a monthly dinner in which the guest who brings the biggest buffoon gets a career-boost. Tim plans on not attending until he meets Barry, a man who builds dioramas using stuffed mice. Barry's blundering but good intentions send Tim's life into a downward spiral, threatening a major business deal and possibly scuttling Tim's engagement to his fiancee.