In all fairness. Taeha tried to make it all fair for everyone. He didn't make his move, not until Mincheon was the one who did incredibly stupid and cheating right out in the face of Haesoo, leaving her all alone again.
In this way, he is letting Haesoo's feelings towards Mincheon fade away. So he can have her all to himself. After all, its not just some months or years. It's a decade of feelings bottled up.
In all fairness. Taeha tried to make it all fair for everyone. He didn't make his move, not until Mincheon was the one who did incredibly stupid and cheating right out in the face of Haesoo, leaving her all alone again.
In this way, he is letting Haesoo's feelings towards Mincheon fade away. So he can have her all to himself. After all, its not just some months or years. It's a decade of feelings bottled up.