He seeks to dominate not only the women, but the other men as well. He beats his pregnant wife. And yet Stella comes back. Something about Stanley excites her, even, or perhaps especially, when he is at his most beast-like. Significantly, what we see of their making-up is completely wordless.
Words come second, if at all.
The bond between Stanley and Stella is not intellectual, but physical. The next morning. Blanche stayed at Eunice's last night. When Stanley is gone, she rushes into the Kowalski apartment, frantic with worry. Blanche simply cannot understand how Stella could return to a man who beat her.