Fry the bacon in a skillet over medium-high heat until crispy.
Transfer the bacon to a paper towel lined plate, and leave the grease in the pan.
Add the Brussels sprouts to the pan, stir them until they're nicely coated in the bacon grease, and cover the pan with a lid. Reduce the heat to medium-low. Cook for 5 minutes.
Add the bacon back into the pan. Cook, uncovered, for a few more minutes or until the Brussels sprouts are as tender and/or browned as you want. You can cover the pan again if you wish (especially if you want the Brussels to be super soft); just keep an eye on them so they don't scorch.
Season with salt & pepper if needed. Serve immediately.