Bring a large pot of salted water to a boil. Add the fettuccine pasta and cook according to package instructions until al dente. Drain and set aside.
While the pasta cooks, heat the olive oil in a large skillet over medium-high heat.
Add the shrimp to the skillet and season with salt, black pepper, and red pepper flakes. Cook for 2-3 minutes on each side until the shrimp turn pink and opaque. Remove the shrimp from the skillet and set aside.
In the same skillet, reduce heat to medium and add the minced garlic. Sauté for about 1 minute until fragrant, being careful not to burn the garlic.
Add the unsalted butter to the skillet and allow it to melt.
Pour in the heavy cream and bring it to a gentle simmer. Cook for 3-4 minutes, stirring occasionally, until the sauce begins to thicken.
Stir in the grated Parmesan cheese until melted and the sauce is smooth.
Return the cooked shrimp to the skillet and toss to coat them evenly in the cream sauce. Cook for an additional 1-2 minutes to heat through.
Add the cooked fettuccine pasta to the skillet and toss everything together until the pasta is well coated with the creamy shrimp sauce.
Remove from heat and sprinkle the chopped fresh parsley over the pasta.
Serve immediately while hot.