Heat a Lodge 12-inch cast iron skillet over medium heat for I minute. Add the bacon, and cook, stirring a few times, until it is crisp and the fat has ren­dered. Using a slotted spoon, transfer the bacon to a paper towel-lined plate to drain.
Add the butter and oil to the bacon drippings, and heat over medium-high heat until the butter melts. Add the scallops, and cook for 60 seconds on one side--do not touch. Flip the scallops, squeeze the lemon juice over them, and cook for another 60 to 90 seconds, until the scallops are just firm to the touch.
Remove the skillet from the heat, plate, and pour the pan drippings over the cops of the scallops. Sprinkle with the bacon and parsley as desired, and serve.