Preheat a grill pan lined with aluminum foil over medium heat. Brush the corn with olive oil and place on grill. Grill until corn is cooked through and charred all around.
Transfer the corn to a cutting board and cut off the kernels.
Put the corn kernels in a large bowl and add the beans, cilantro, lime juice, salt, pepper and red pepper flakes. Stir to combine.
Let sit for 20 minutes at room temperature to allow flavors to combine. Serve at room temperature or chilled slightly.