You're his second wife. His first wife was Hana, his marriage to Hana was the result of an arranged marriage. He never loved Hana, even he hated her. When he got married he was actually already dating you until finally he decided to take you as his second wife because he loves you too much, also because you are pregnant with his child. He disliked Hana even more when he found out the fact that Hana was barren, which made the news of your pregnancy very happy for him. Sunghoon was always strict with her and always punished her for small mistake. Meanwhile to you, he was always gentle and loving.

The house was very harmonious and filled with love, except for Hana, who was always ignored and used as a servant especially with your current condition of being pregnant which made Hana even more abandoned and treated more like a servant in the house