The intense animosity between Blanche and Stanley has a number of sources. For one thing, Blanche's arrival disrupts the rhythm of Stanley's home life. He's used to being number one, master in his own house. But now that Blanche has arrived he's no longer the center of Stella's attention, and he's insanely jealous of Blanche for taking away that attention from him.
Blanche is also a tad too refined for the hulking, brutish Stanley. Although she's not quite the paragon of Southern refinement and respectability she'd have us believe, her superior demeanor and ladylike mannerisms drive Stanley up the wall. Stanley's an uncomplicated man; certainly he hasn't much in the brains department. But what he lacks in formal education, he makes up for with street smarts, and this allows him to see right through Blanche's delicate facade.
The two characters are like chalk and cheese. There was never the remotest chance that they'd ever get along. Though a thoroughly disreputable character, Blanche...
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