 Marilyn is very depressed, because all her boyfriends run away when they meet Herman. But Marilyn thinks that is all her fault and maybe there s something wrong with her. Grandpa wants to help her, preparing a sort of love potion, with all kind of ingredients, like a woman tear or Frank Sinatra s charming. Meanwhile, the postman and Yolanda Cribbins, the neighbour, are talking very bad about the Munster family. The postman is very afraid of delivering the mail at the Munsters  house, while Misses Cribbins thinks that the neighbourhood uses to be nice, until the Munsters arrive. Next morning, Grandpa is planning to pour his love potion on Marilyn s plate. There will be oatmeal for breakfast. Grandpa pours out the potion on the plate. But Marilyn leaves without having her breakfast. Lily will return all Marilyn s oatmeal to the saucepan. Herman, Lily and Eddie will eat the oatmeal with the love potion. The potion starts to make effect. Herman and Lily become seductive for each other. In his way to school, Eddie will be chase by a bunch of girls, trying to catch him. At the garden, Misses Cribbins will find Herman very attractive, while the postman starts to flirt with Lily. During the night, they will receive the visit of the postman and Misses Cribbins, whom start chasing inside the house both Herman and Lily, trying to seduce them. Grandpa finds out what is happening, when Marilyn tells that she hadn t oatmeal that morning. As a matter of fact, Misses Cribbins asks Herman to call her "Yo-Yo". However, when the effect passes, the postman and "Yo-Yo" will see Herman and Lily as they are. So, they will run away from the house. Marilyn tells Grandpa that she prefers to be herself, instead of drinking love potions.