Instructions:

1. Cook the pasta: Bring a large pot of salted water to a boil. Add the fettuccine pasta and cook until al dente according to the package instructions. Drain the pasta and set aside.

2. Cook the shrimp: In a large skillet, melt 2 tablespoons of butter over medium-high heat. Add the shrimp to the skillet and cook for 2-3 minutes per side until they turn pink and are cooked through. Remove the shrimp from the skillet and set aside.

3. Prepare the Alfredo sauce: In the same skillet, melt the remaining 2 tablespoons of butter over medium heat. Add the minced garlic and cook for 1-2 minutes until fragrant, stirring frequently to avoid burning.

4. Add the heavy cream to the skillet and bring it to a simmer. Let it cook for about 2 minutes, stirring occasionally.

5. Gradually whisk in the grated Parmesan cheese until it melts and the sauce becomes smooth.

6. Season the sauce with salt, black pepper, and red pepper flakes (if desired), adjusting the seasonings to your taste.

7. Add the cooked shrimp back to the skillet and stir to coat them evenly with the sauce. Cook for another minute or so until the shrimp are heated through.