Responses
That's an interesting theory but from what I've seen it looks like the sister may have deliberately set up that situation with her brother and Liu Ye. Remember, she quit the job she signed on with pretty much around the same time she got the contract with them only to sign with Liu Ye's company?
If she did that it doesn't make sense that she would try to put the guy she's stalking with her brother.
What if the sister is in love with her brother and that's why she's so jealous and that's her secret