Bring a large pot of lightly salted water to a boil. Cook elbow macaroni in the boiling water, stirring occasionally until cooked through but firm to the bite, 8 minutes. Drain.
Place bacon in a large skillet and cook over medium-high heat, turning occasionally, until evenly browned, about 10 minutes. Drain the bacon slices on paper towels and dice.
Preheat oven to 400 degrees F (200 degrees C).
Stir Cheddar cheese soup, Cheddar cheese, and milk together in a bowl. Stir pasta, bacon, and lobster into soup mixture. Pour pasta mixture into a 2 1/2-quart shallow baking dish.
Mix bread crumbs and butter together in a separate bowl; sprinkle over pasta mixture.
Bake in the preheated oven until bubbling and bread crumbs are lightly browned, 25 to 30 minutes.
