Add garlic and corn; cook for 1 minute. Transfer vegetables to a bowl.
Add remaining oil to the skillet. Cook shrimp in a single layer, seasoning with salt, pepper, and Cajun seasoning, until pink, about 1-2 minutes per side.
Return vegetables to the skillet, add lemon juice, and toss to combine. Garnish with parsley before serving.
Notes
Adjust seasoning to taste and serve hot for best flavor.