In a large skillet heat oil over medium high heat. Stir in onion and cook for 2 minutes. Add garlic and cook for 30 seconds. Add white wine and simmer for 2 minutes. Stir in tomato sauce and red pepper flakes. Bring sauce to a simmer and stir in the shrimp. Cook for 1 minute and stir in scallops. Simmer for 2 minutes. Stir in parsley and toss with pasta. Serve immediately.