Honestly, seeing Pei Yang so obsessed with her just surprises me, because not once in their time when she still thought highly of him, did he not use her. Now, he is all flashbacks and memories, but not once did he save her for just simply saving her life, but to catch the assassin. That's why the first time he didn't let her leave, I did not register that it was at least partly because he fell for her. I just thought he liked her enough to feel maybe a little guilty for using her, not that he was actually catching feelings. And despite him continuously showing a grey character, I did not expect that he would actually be so obsessed and entitled to hold her captive.
I cant start this drama until they fall in love or starts relationship ..after watching 10+ episodes of using…
I mean around ep 12-13 he stops thinking of her death and rather has her alive, I'd say with the newest episodes (14 and 15) it's noticeable that he starts liking her.
At this point, being so close to kissing, it's more embarrassing to not do it at all. They looked each other so deep into the eyes, you cannot even pretend that it wasn't on your mind.
Edit:
maybe not really love, but more of an admiration that had the potential to turn into love because there were a few romantic glances