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"Sister Mom"
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"Sister Mom"
"The Laughing" The Laughing
Sister Mom
Season 2, Episode 23a
Episode name reference to/pun on: The 1983 film Mr. Mom
Sister Mom
Air date January 21, 1998
Production number 227a
Written by Paul Harrison
Storyboard by Craig McCracken
Directed by Rob Renzetti
Genndy Tartakovsky

Sister Mom is the first segment of the twenty-third episode in season 2 of Dexter's Laboratory. It first aired on January 21, 1998.

In this episode, Dexter gets sent home with a note about a parent-teacher conference from the school principal that he must show to Mom. Instead of taking Mom to the conference, Dee Dee goes in Mom's stead. However, before and during the conference, trouble arises when Dee Dee, disguised as Mom, starts misbehaving.


Dexter and Dee Dee are walking home from school. Dee Dee takes the letter out of Dexter's hand and reads it aloud, making Dexter flinch. After arriving home, Dexter advises Dee Dee to make no mention of the parent-principal conference to Mom, who then opens the front door. While Dexter walks to his room, Mom tries to enlighten his mood, but instead makes Dexter run to his room crying in embarrassment.

To avoid having Mom go to the parent-principal conference, Dexter tries to come up with an idea, only for him to be greeted by Dee Dee standing on his bed ready to pounce him. As Dee Dee leaves, she gives Dexter an idea that makes Dee Dee go in Mom's place. They go inside Dexter's lab where he introduces Dee Dee to the Molecular Makeover Machine. Dee Dee turns down the idea, but quickly changes her mind after Dexter tells her she won't find out what he did.

To aid her brother, Dee Dee steps inside the Molecular Makeover Machine and watches as it transforms her into Mom. Once the transformation is complete, Dexter and Dee Dee race over to Huber Elementary on Dee Dee's bike, where they wait outside the principal's office. Dexter advises Dee Dee to act like a proper parent, to which she does so by embarrassing Dexter. In response, Dexter punches Dee Dee and is given a thumbs-up from the other kids. Soon after, Dexter and Dee Dee go into the principal's office where the conference begins.

During the conference, Dee Dee's erratic behavior starts annoying Dexter, and when the principal reveals that Dexter got an A minus, Dee Dee realizes that the whole idea was pointless; in which Dexter counters that if his "stupid sister" would stop bothering him all the time then he wouldn't have even gotten that A minus. Her argument with Dexter soon turns physical as they both beat each other up. To the dismay, the principal pleads for them to stop and sees why Dexter and "Mom" fight all the time. He then suggests that they (and Dee Dee) should have a conference with the school counselor.

During the meeting with the counselor, Dexter, inside Dee Dee's body acts silly then repeats "Dee Dee dumb" continuously. Dee Dee, who still looks like Mom, orders him to stop. A dog inside Dexter's body pants and scratches himself with Dexter's boot. The counselor sees nothing wrong with them and goes with the principal to get some lunch.



Dexter Daddy Picture
The Domestic Family
Domestic Abuse in Dexter's Lab



  • None known.


  • When Dexter goes into his room crying, he doesn't have the note in his hand. However, after entering, the note is back in his hand.
  • Outside the principal's office, the girl with orange hair is shown to have a black eye. However, after Dexter punches Dee Dee, her black eye is gone.

Episode connections[]

  • This is the Principal's first physical appearance since the episode "Dexter's Rival", where he only spoke on the intercom.

Cultural references[]

  • While activating the Molecular Makeover Machine, Dexter says; "It's morphin' time!", similarly doing the gesture that the character Jason Lee Scott and his friends do in the Power Rangers franchise.
  • The song "Sabre Dance" by Aram Khachaturian, more notably its final movement, plays while Dee Dee rides her bike to Huber Elementary.

Production Notes[]

  • This episode alongside "The Laughing" are the first two episodes without a mini-segment.