Bring a large pot of salted water to a rolling boil, cook the pasta until al dente, drain well, and set aside.

Heat a large skillet over medium heat and add the olive oil and butter, letting the butter melt and coat the pan evenly.

Add the shrimp in a single layer and cook for 2 to 3 minutes per side until pink and opaque, then remove and set aside.

Add the minced garlic to the same skillet and cook for about 1 minute, stirring constantly until fragrant.

Pour in the heavy cream and bring it to a gentle simmer over medium low heat, stirring often to avoid scorching.

Stir in the Parmesan cheese and Cajun seasoning until the sauce becomes smooth and slightly thickened.

Gently fold the crab meat and cooked shrimp back into the sauce, keeping the crab in tender pieces.

Add the cooked pasta to the skillet and toss until the noodles are evenly coated with sauce.

Season with salt and black pepper, adding a small squeeze of lemon juice if desired.

Remove from heat, sprinkle with fresh parsley, and serve hot while the sauce is creamy.