Remove bacon & place on paper towel, but save 2 tablespoons bacon drippings in skillet. Crumble bacon; set aside. Stir vinegar and sugar into reserved drippings; heat to a boil scraping bits as you go from bottom of skillet. Add spinach mixture to skillet. Toss 1/2 to 1 minute until spinach begins to wilt. REMOVE FROM HEAT.