Dude same thoughts, like I noticed in the earlier chapters when her mom would ask how theyre doing its always after something happened between rosa and yeonwu.
Honestly, im also doubtful that her mom is unaware, theyre rich so its not impossible that theres hidden cameras somewhere there.
Just some idea, i have a feeling that her mom brought yeonwu there for rosa, she might have ntr kink lol, but this might just be a useless take my brain might be fried from all the yaoi ive been reading

It’s more eerie and bloody than the seductive red + bdsm cover we got from the last. Anyways, I’ve never seen Rosa wear a long skirt. Her mom does though. Rosa’s whereabouts is more likely to be the one where Yeonwu’s chains are coming from. I also don’t think Rosa can beat Yeonwu up that badly just for the funsies. After all the hide and seek shenanigans from the first season, are we already on the “when we get found out by mom”? I’m sure this won’t strain the sociopath mother-and-daughter relationship much more than what’s coming for Yeonwu lol.
I can’t help but notice that the stairs as the setting is also a deliberate choice by the author. It’s there in Rosa’s “do you love me” dream in Chapter 1, their first reunion after years, when Yeonwu got drugged up and mistook Rosa for her mom, and Rosa’s proposal to Yeonwu to either get his revenge from her mom or her.
Mommy knows obviously. One of the staff is already talking and you can’t tell me there’s no security cameras installed when she has bodyguards tailing her due to her shady businesses. A surprise day off from a cold missus and a young husband-to-be quickly after the mom boarded the plane is already a juicy staple for the house’s staffs. I don’t see both Rosa and Yeonwu treating this as a serious affair yet and the mom is letting them off easy. We’ll see how this mess plays out.