For people how are confused: Heeju married the ML not because her sister ran away but because the sister tried to blackmail him to stop the wedding and help her go abroad, she couldn't get to him though, so they made a kind of an agreement, if she got Heeju to be his bride, he would help, and the sister agreed.
The sister was using the fact that the ML is not "Baek Sa-eon" which was something she noticed when she was young, but right after she said that when she was young the car accident, which she lost her hearing because of, happened which was clearly a warning
The sister was using the fact that the ML is not "Baek Sa-eon" which was something she noticed when she was young, but right after she said that when she was young the car accident, which she lost her hearing because of, happened which was clearly a warning
🍉🍉