From the beginning it is shown that Lin Xioa Run's mom liked Chen Shi Yun and she kinda pushed her son towards…
She’s probably asking to make sure he DIDN’T like her as a GF because she knew they could possibly be step-siblings - even CSY’s dad asks her if she likes LXR and she emphatically says no. They probably wanted to make sure their kids had just a sibling relationship and not more since they were involved and knew it would make things hard for their kids if they married knowing they liked each other as BF/GF.
I’m on ep 5 and not feeling the chemistry at all between leads. Like everyone else I like Riley but the FL just doesn’t do it - I’ve seen a couple of other dramas with her and didn’t like them either..I don’t know what it is about her - and the character she plays in this one is just not very nice.