In a medium bowl, combine the peeled and deveined medium shrimp with olive oil, lemon juice, minced garlic, paprika, red pepper flakes, salt, and pepper. Toss to coat and marinate for 10 minutes.

Heat a large skillet over medium-high heat. Add remaining olive oil and butter, allowing to melt until shimmering, about 1-2 minutes.

Add the marinated shrimp and lemon slices to the skillet in a single layer. Cook for 2-3 minutes on one side until they turn pink and opaque.

Flip the shrimp gently and cook for another 2-3 minutes until firm and completely opaque.

Remove from heat, transfer to a serving platter, and garnish with parsley. Serve warm.