Pour olive oil into a heavy skillet over medium heat, add bacon and cook until almost crisp (5-8 minutes). Remove all but 2 Tbsp bacon drippings, and turn off heat. Stir in garlic and lemon and cook until fragrant, 2-3 minutes, add sour cream and warm pasta. Return heat to medium and add tomatoes and arugula. Season with salt, pepper and cayenne pepper and garnish with parmesan cheese.