Cook pasta in salted water according to package instructions. Reserve ½ cup pasta water, then drain.
Heat olive oil in a large skillet over medium heat. Add shrimp, season lightly, and cook 2–3 minutes per side. Remove and set aside.
In the same skillet, add asparagus and cook for 3–4 minutes until tender-crisp.
Add garlic and cook for 30 seconds until fragrant.
Pour in cream and simmer gently for 2–3 minutes.
Stir in parmesan cheese until smooth.
Add cooked pasta, shrimp, and a splash of pasta water if needed. Toss well.
Finish with black pepper, red pepper flakes, and lemon juice if using.