Stanley is Stella's husband, a former military man, a lower-level worker, “a great breeding producer,” who appears in the book as the opposite of the main character. Vital, coarse, sensual, accustomed to humor himself in everything, Stanley Kowalski is a monkey man, with a sleeping soul and primitive inquiries. He "acts like an animal, has an animal's habits! Eats like one, moves like one talks like one! There's even something sub-human, something not quite to the stage of humanity yet". He was accustomed to be the sovereign in the house and to lead among his friends. In his eyes, Blanche is a threat to all of his lifestyle, moral standards, control over what is happening and relations with Stella. That is why he hardly tolerates the appearance of an unexpected and uninvited guest at his home and begins with her the struggle both physical and psychological. Stanley reveals all the secrets from the past life of Blanche and spoils, as it seemed, the newly established life.
Her "cultural" manners are alien and repulsive to him. Her fantasies sound to him a falsehood, cunning pretense and hypocrisy; he scoffs at her "noble," "secular" claims, the very place of which is in the "crappy junkman." Stanley, the doer of violence, is driven by the desire to crush Blanche with her hated ideal world, who, despite everything, lives in her restless soul. And he is driven by the desire to generally get even with the arrogant Dubois, who condemned Stella for her choice. Thus, he wants to show all his disregard for this elite.
Outwardly, he is an adherent of the traditional moral principles of the average person, but in reality, he does not disdain to spend the night with a new woman, beat his pregnant wife and rape her sister as soon as his wife left home to give birth. After all, he probably knew that it would be nothing for him.
Stanley Kowalski in the Essays