Sharing

"Sharing" is Episode 7 in Season 4.

Synopsis
Mort comes for yet another visit and he and Muffy have a good time sharing. But later, a fight breaks out between them and they don't want to speak to each other. So Muffy uses a magic spell to get a new friend who suddenly appears, a mouse named Lucille. But she makes Muffy madder when she becomes friends with Mort. Eventually, Muffy and Mort fight over her until she disappears and they finally make up and agree to share from now on.