Bring beans and 8 cups water to a boil in a large pot. Season with salt.
Reduce to a simmer and cook until tender, 20 to 25 minutes.
Add corn and cook just until tender, 4 to 6 minutes.
Drain any excess liquid and return beans to pot.
Add cream and cook until slightly thickened, 2 to 3 minutes.
Remove from heat and stir in butter.
Season with salt and pepper.
