In the scene where Michael is hosting Geary and others in the Havana nightclub, Fredo asks if the guests want more drinks. Geary says, leeringly, "I'll try one of those red-headed Yolandas" [the showgirl we saw earlier]. If you run that scene very slowly, the camera pans onto Michael's face, and he's rolling his eyes as if to say, "Geez, doesn't this guy ever keep his dick in his pants?"