Bring a pot of salted water to a boil and cook the spaghetti according to package directions until al dente. Reserve a bit of the pasta water before draining.

In a large skillet, heat olive oil and half the butter over medium heat. Add the minced garlic and sauté for about 1 minute until fragrant.

Toss in the shrimp, red pepper flakes, salt, and pepper, cooking until the shrimp turns pink (about 2-3 minutes on each side).

Pour in the white grape juice and lemon juice, scraping the bottom of the pan to deglaze. Allow the sauce to simmer for about 2 minutes before reducing the heat and adding the remaining butter.

Add the drained spaghetti to the skillet, tossing to combine. If the dish seems too dry, add a little reserved pasta water to create your desired consistency.

Garnish with chopped parsley before serving.