The Simpsons (1989): Season 27, Episode 6

27 - 6: Friend with Benefit

Lisa befriends Harper, a new kid at school who happens to be super-rich. Then, Homer befriends Harper's dad and is able to enjoy the perks of Lisa having a rich friend, as well. But Lisa decides that Harper is a bully and moves to end the friendship, which prompts Homer to try and smooth things over so he can continue to enjoy the good life.