Clean and devein shrimp. Set aside. Trim asparagus and snap into two or three pieces.
In a large pot, bring 2 quarts of water to a rapid boil. Generously salt water. Add pasta and cook uncovered, stirring occasionally, for about 10-15 minutes or until pasta is al dente. Remove from heat. Drain.
While pasta is cooking, add the olive oil to a skillet over low-medium heat. Add garlic and red pepper flakes and cook until fragrant.
Add asparagus and cook until slightly tender but firm; remove from pan. Add shrimp and cook until pink. Return asparagus to the pan.
Stir in lemon juice. Salt and pepper as desired. Toss mixture with pasta. Top with freshly chopped parsley.
For a richer flavor, replace 1 or 1-1/2 tablespoons of extra virgin olive oil with unsalted butter.