Cook fettuccine by boiling salted water. Once boiling, add fettuccine and cook until al dente, about 8-10 minutes. Drain and set aside.

In a large skillet, heat olive oil and butter over medium-high heat. Season shrimp with salt and pepper, then sauté for 2-3 minutes per side until pink. Remove shrimp and set aside.

In the same skillet, reduce heat to medium and add remaining butter. Once melted, add minced garlic and sauté for about 1 minute until fragrant. Pour in heavy cream and simmer for 3-4 minutes until thickened.

Lower heat and stir in Parmesan cheese until melted and the sauce is creamy. Season with salt, pepper, and optional red pepper flakes.

Combine cooked fettuccine and sautéed shrimp into the Alfredo sauce, tossing gently until well coated. Use reserved pasta water to adjust consistency if needed.

Serve immediately, garnishing with chopped parsley for added flavor and color.