ESTELLE COSTANZA

'Estelle Costanza' (played by Estelle Harris) is a fictional character on the US television sitcom ''Seinfeld'' (1989-1998). She is the mother of George Louis Costanza and is married to Frank Costanza. George has once stated that in his life, he has never heard her laugh.
The stereotypical overbearing, obnoxious sitcom mother, Estelle spends virtually all her time screeching at Frank and George. She and Frank have a love-hate relationship: they seemingly can't stand each other, and yet stay together out of habit (or because no one else can stand ''them''.) They were briefly separated, however.
George lived with Frank and Estelle until well into his adult life. He is often humiliated by her very existence, and largely blames her for his being a neurotic failure. He is still emotionally tied to her, however. During his parents' separation, he fretted constantly over the collapse of his family — not because he loved or even ''liked'' them, but because he couldn't stand the thought of his parents being "out there" in the dating world with him. He also finds the idea of making two visits on holidays to be entirely distasteful.
She maintains cool, distant relations with Jerry's parents, Morty and Helen, because she thinks they are snobs. The Seinfelds do in fact avoid the Costanzas, not out of superiority, but because they can't stand them. She has a flirtatious friendship with George's friend Kramer, however, which is the source of much friction between her and Frank.
In fact, Frank and Estelle sleep in separate beds (at least some of the time, although George did have sex in ''their'' bed in "The Cigar Store Indian"), not because of marital problems, but because Estelle has "the jimmy-arms," according to Frank ("The Money").
Although Estelle's religion was never mentioned on the show, both Larry David and Jason Alexander considered her to be Jewish. David referred to George as "half-Jewish" in an interview [1], and Alexander stated that he had no fixed ideas about George's ethnicity until the casting of Harris as his mother, and said that "she can't be anything but Jewish." [2] In "The Strike," Frank Costanza refers to the genesis of Festivus as springing from an occasion in which he was buying a Christmas gift for George, showing that Christmas was celebrated in the household. In another episode, Estelle refuses to allow Frank to purchase a Mercedes because she "won't ride in a German car", which is a position taken by some Jewish-Americans uncomfortable with the automaker's link to Nazi Germany.
Estelle has thwarted George's chances at dates many times (example being in "The Cigar Store Indian.") She believes almost everything that is important to George and her husband is stupid (such as Frank's TV Guide Collection).