Grandparents' Day (A Low-Cost Outing for Seniors) was an event in which Springfield Elementary School students brought a grandparent to school. Among other things, Nelson brought a judge, and Milhouse brought a man who travels the country in an RV. Unfortunately, Bart was saddled with his senile paternal grandfather, as his maternal grandfather is deceased and it seemed that kids only brought a grandparent of the same gender; if the second grade took part, it can be safely assumed that Lisa brought Jacqueline Bouvier.