He was a narcissistic arrogant misogynistic jealous bastard. He knew it. He loved having controll over everyone.

He worked at a Wall Street investment firm of Pierce & Pierce, he was the CEO. His old assistant quit her job and he got a new assistant. She was annoying, she made him question his beliefs, she was smart and independant, she was better than him, it irked him.

He could easily fire her but he chooses not to maybe because he caught feelings, Maybe (he was already deeply in love).