In that wonderfully acted scene when Michael and Fredo have their drink in Havana: Fredo is on the verge of intimacy. He says, "Sometimes I wish I would have married a woman like Kay...be more like..." We're waiting for Fredo to say, "...like you." Instead, he says, "...like Pop." He's holding Michael's wrist, but then he jerks it away and says, angrily, "Why didn't we spend time like this before?" Cazale's triumph.