The Simpsons season 28 episode 20
Episode title: Looking for Mr. Goodbart
Bart gets in trouble on Grandparents Day at school and is forced to hang out with Skinner's mother as punishment. After spending time with various grandmas in the neighborhood, he learns the benefits of hanging out with the elderly, but eventually recognizes the dangers of taking advantage of them. Meanwhile, Peekimon Get has taken over the town of Springfield.