Edna Krabappel is Bart’s jaded teacher. She is often seen smoking in her green sweater, making sarcastic comments and generally not caring about anything. She is the worn down, baggy-eyed product of the American public school system. Beneath her lacklustre demeanour, however, lies a passionate, caring individual. These two radically different Edna’s exist because Edna keeps her private and public spheres discrete.
Outside of class, Edna is a completely different person. She is lonely and often desperate for male attention. This results in her apparent promiscuity. She is seen making out with a Japanese chef in “One Fish, Two Fish, Blowfish, Blue Fish” and trying to aggressively seduce Aerosmith’s Joey Kramer in “Flaming Moe’s.” She even comes onto Homer in one episode.
As mentioned earlier, Edna’s teaching style does not reflect this at all. Occasionally she slips up, letting her private life into the public, but she recognizes her mistakes. After Bart ruins one of her dates, she says, “Ugh, that’s the last time I announce my dinner plans in class.” She obviously realizes her blunder.
But even though she gives off a licentious vibe, Edna is really looking for a true relationship. She falls in love by mail with Bart’s alter-ego, Woodrow, in a cruel prank. She’s not just looking for sex, but a deep emotional relationship. She also falls in love with Principal Seymour Skinner, and that’s when her problems really begin.
Her relationship with Skinner presents the threat of her private life becoming public. After Bart finds out about their relationship, she must find a way to keep him quiet. She and Skinner take advantage of Bart and use him as a tool to keep their relationship private by forcing him to carry secret letters and distract people while they sneak away together. Bart becomes fed up and reveals their affair. Krabappel’s life becomes miserable. She and Skinner are ridiculed, rumoured about and chastised by the entire town, and Superintendent Chalmers forces them to choose between their profession and their love.
The only way to save Edna’s private life is to sacrifice Skinner’s. He has to admit to Springfield that he is a virgin, revealing his most private of details. Of course, this is not true, but Skinner has to endure the appearance of his private life becoming public in order to save their relationship.
This is the only way they can continue their relationship — in private — the way Edna always wanted it to be.