Place corn into a large pot and cover with salted water; bring to a boil. Reduce heat to medium-low and simmer until tender, 10 to 15 minutes. Drain and cool corn. Cut corn off the cobs.
Place squash into a skillet and add water. Cook squash over medium heat until tender, 5 to 10 minutes. Drain any excess water from skillet.
Stir corn, butter, parsley, salt, and pepper into squash; cook, stirring occasionally, until heated through, about 5 minutes.
