Heat grill to medium-high. In a small bowl, combine the oil, parsley, vinegar, garlic, red pepper, and ¼ teaspoon salt; set aside.
Season the steak with ½ teaspoon salt and ¼ teaspoon pepper.
Grill the steak, 4 to 5 minutes per side for medium-rare. Let rest 5 minutes before slicing.
Meanwhile, grill the corn, turning occasionally, until slightly charred, 3 to 4 minutes. Serve with the steak and sauce.