Dexter's Laboratory Wiki
Advertisement

In the episode Dee Dee's Rival, there is a girl in Dee Dee's dance class that sort of resembles Douglas (similar height, buck teeth, glasses) that could possibly be Douglas' sister. Since later in the episode in the concert, she goes out on the stage and does a solo. Then out in the audience, the girl's mother tells Dexter's mom that that is her daughter in the purple tutu. Which reveals that if the girl was Douglas' sister, her mother would be Douglas' mother which would take care of that mystery.

Advertisement