Lu Beiyuan is very clear about what his father means.
Xie Fengting is simply anxious and wants him and Lu Nianxi to get closer.
But Lu Beiyuan doesn't want that.
Lu Nianxi likes him, that's undeniable.
But her feelings for him are more like family, no different from her feelings for Lu Nuanyang and Lu Hongze.
She's called him brother since she was young, and she really sees him as a brother.
Actually, Lu Beiyuan also knows that even real siblings can't be as attentive to each other as he is to Lu Nianxi.
Some things even go beyond what a brother would feel for a sister.
For example, he can freely enter and exit Lu Nianxi's bedroom.
He can open her wardrobe to prepare her clothes.
He blows her hair and braids it.
When her shoelaces come undone, he squats down and kneels on the ground to tie them.
Of course, these are not normal... no brother would go to such lengths.
But because he's been doing this since childhood, Lu Nianxi doesn't find anything wrong with it.