Cook the bacon in a large skillet over medium heat. Cook for 5-7 minutes, flipping once, until both sides are browned. Remove from pan and place on a paper towel lined plate. Crumble.
Add the zucchini, squash, and onions to the pan with the bacon drippings. Saute for 3-4 minutes or until the vegetables begin to soften.
Add in the garlic, butter, lemon juice, salt, and pepper and cook, stirring frequently, until the butter has melted.
Continue cooking for 1-2 minutes or until the vegetables are translucent.
Remove from heat and stir in crumbled bacon.