A terrified and desperate Bukharin says that he and his wife are being arrested for some unknown reason. Stalin asks how this can be since he ordered no such thing, telling Bukharin to put the commanding secret police officer on the line. Stalin chews the man out and tells him to leave Bukharin and his wife alone.
Stalin's side of the conversation plays out like a comedy act in the presence of his snickering cronies. As Stalin puts the receiver down, he chuckles "and they say Comrade Stalin has no sense of humor."
I have read of instances in which FDR similarly delighted in humiliating rivals, enemies, and even friends. I do not mean to suggest that Stalin and FDR are equivalents, only that both seemed to sometimes show a feline sense of malice and delight in using their power to toy with others. Alas, I doubt that anyone will produce a film showing that unsettling aspect of FDR's character.
Also the scene were Beria comes into the room, with Stalin and the rest of the Politburo, mocking and crying like Zinoviev did when he was pleading for his life before Beria shot him.
Of course the story is, when it was Beria’s turn to go, he cried like a little bitch, too.