In the same skillet, add the wine and lemon juice. Simmer for 2 minutes. Add garlic. Continue to simmer, stirring occasionally. Add cold butter once white wine-lemon juice has been reduced to half. Stir until smooth and creamy.
Add fresh parsley, shrimp, and red pepper flakes. Sprinkle salt and black pepper, as desired. Turn shrimp after 30 seconds. Turn off heat once shrimp has been heated through.