Preheat your grill to medium-high heat.
In a mixing bowl, combine the melted butter, minced garlic, chopped parsley, lemon juice, red pepper flakes, salt, and pepper. Mix well.
Place the shucked oysters on a grill-safe tray or directly on the grill grates.
Spoon the garlic butter mixture generously over each oyster, then top with grated Parmesan cheese.
Grill the oysters for about 5-7 minutes, or until the cheese is bubbly and golden brown.
Remove the oysters from the grill and let them cool slightly before serving.
Serve with lemon wedges on the side for an extra burst of flavor.