Yeonjo is determined and stubborn, he needs to honor his family's memory by taking revenge until the end. And the Lord is not stupid, he knows that keeping Yeonjo by his side this will happen one day whether he wants it or not. But my guess is, the Lord will give his life to save Yeonjo, he dies from a trap created by Yenojo, then Yeonjo realizes he loves him. This is the only appropriate redemption for the Lord, so Yeonjo feels like he has avenged her family's death, runs away after the incident but he doesn't know that the Lord survived... and so begins the race for their happiness.
Yeonjo is determined and stubborn, he needs to honor his family's memory by taking revenge until the end. And the Lord is not stupid, he knows that keeping Yeonjo by his side this will happen one day whether he wants it or not. But my guess is, the Lord will give his life to save Yeonjo, he dies from a trap created by Yenojo, then Yeonjo realizes he loves him. This is the only appropriate redemption for the Lord, so Yeonjo feels like he has avenged her family's death, runs away after the incident but he doesn't know that the Lord survived... and so begins the race for their happiness.