@Lemongrassv
Maybe cause of how family oriented most of east asia is.
I mean, when that exact same thing happens with a fiance, MC usually finds a better man.
When it's the dad he's just "misunderstood".
At least in this one, the duke is pretty clearly reacting to her daughter doing a 180 on her feelings for him, combined with ominous nightmares he half remembers of what happened in the future.
And it's not all misunderstandings and shit where he actually secretly "adores his precious baby girl" like in some other manhwas.