ahhh, his wine... good answer :P
Seriously, what I remembered from the novel is that YLS was LHC first love and vice versa. Almost like kiddie love (they even created useless swords arts together).
YLS was the first to move on. She fell in love with her true love.
Then LHC, broken hearted, also moved on. He found this amazing girl ( who btw is better than YLS in every aspect ). Through thick and thin, they fall in love. RYY was first to show affection, LHC soon followed.
If anyone still have doubt, remember that:
1. LHC dreamed about RYY, not YLS, before awaken by XWT.
2. RYY is the first girl to be able to move LHC's heart so great that he could not resist to kiss her instantly. (we're talking about a man who can control his manner in front of ladies here)
3. LHC, enjoying chat and being together with RYY so much, forgot that he's supposed to protect YLS (RYY herself have to remind him of this).
4. LHC explicitely told Yi Lin's mother that RYY is the love of his life.
5. LHC can accept YLS death, although very sad, but can not stand the thought of losing RYY (he was about to take his own life in that cave).
6.... that's all I can remember for now.