Arthur was out for words. Actually, he is not used to saying such words. It was the first time that he spoke about relationships with someone. Maybe he felt that his Lady Boss was so down and he just wanted to comfort her. And this was also the first time that he felt the urge to comfort his Boss.
Unlike other spoiled rich that Arthur has met, J has a strong sense of duty. She is not egocentric, she is quite supportive and caring towards the people that are close to her. She is non-confrontational, which is why she is having difficulty dealing with her misunderstandings with Jacob. She is often mistaken as indifferent, cold, and intimidating but the truth is she just prefers doing things alone. She knows what type of people she wants to spend her time with.
