The Berenstain Bears and The Slumber Party is the other Berenstain Bears book written be Stan and Jan Berenstain in 1990
Mama lets Sister go to Lizzie's for a slumber party but Sister finds that Lizzy has got a babysitter. Soon, the sleepover causes havoc and by the time the Bruins comes back, everything a mess. The Bruins are so stern they call the cubs' parents to take them home and they tell them the mess they have made. The sleepover was cancelled, parents were called, Lizzie was sent to bed, and an angry and disappointed Mama Bear came to take Sister home. Mama was so angry and disappointed. Sister is grounded; double grounded. This means she has to stay in her room for one day and in the house for one full week (a week, a month, a year, or possibly a decade, a century, or even a millennium). Papa who thought that the punishment was harsh than tells Mama about how privilege and responsibility applies to parents as well as children. The next day, Mama Bear cancelled the grounding for Sister and they both went over to Lizzy's to help clean up. When Lizzy suggests having some soda and party again (or in other words "having a soda can party") calling it a Clean-Up Party, Sister turns it down saying they must not. Because of the havoc the night before, she says "Let's not". Then Sister tells Lizzy that if Lizzy does not mind, she rather not hear the word "party" again for a long time (saying, "Let's not Lizzy. And if you don't mind, I rather not hear the word party again for a long time".).
Note: In the book, the neighbors called the police after hearing the commotion from the Bruins house. The Chief sent Officer Marguerite to investigate and investigated the simultaneously when the Bruins came home this did not happen in the TV adaption. In the TV adaption, after hearing the commotion the Bruins came home they were so stern that they call the cubs' parents to take them home and then she tells them the mess they have definitely made. But the very next day (in the TV adaption) Sister calls her friends again to have another slumber party but first all they had to do was clean up and then Sister knows what happened the last time Too-Tall and the gang were at the party but then she tells Brother Bear not to invite Too-Tall and the gang anymore.
Note: Slumber parties are a girls-only type thing.