Lovely-me:
Could somebody who has read the novel please, give me a spoiler.
Why is he trying to keep her around? Is there a reason for his behaviour?
I just want to make sure there is a reason, otherwise it feels like a forced script pushing them together for no reason.
Nah
He's doing it so that he can make her go back and fulfill the marriage contract. He was the one who established the marriage contract in the first place, and he needs it to go well, so that some kind of divine world balance can be maintained.
He doesn't know who she is at the beginning, but he doesn't want any of the immortal beings to stay in the lower realm for long... so he's waiting for her to get caught. I think that was it...but it's been too long since I read the novel, so I can't remember it very well.
But I do remember that he planned it so that she would have to go back, cause he was also afraid of falling for her, and that should never happen for the 'balance' to be maintained...