Melt the butter in a skillet over medium heat; mix the corn, green pepper, onion, and curry powder into the melted butter, cover the skillet, and cook until the vegetables are just tender, 8 to 10 minutes. Stir the sour cream into the vegetable mixture, season with salt and pepper, and continue cooking until hot, stirring continually, 2 to 3 minutes. Serve immediately.
