Preheat your grill to medium-high heat.
In a small bowl, combine melted butter, garlic, olive oil, and lemon juice.
Brush the lobster meat and shrimp generously with the garlic butter mixture. Season with salt and pepper.
Place the lobsters shell-side down on the grill and cook for 6–8 minutes.
Add shrimp to the grill, cooking for 2–3 minutes per side until pink and opaque.
Brush with additional garlic butter while grilling for extra flavor.
Remove from the grill, garnish with parsley, and serve with lemon wedges.