People are saying the mom is Haesoo's spy, and while it's suspicious that she's going to the bathroom this often, it doesn't make sense. From the conversation between Haesoo and Jin-ho, their agent was sent recently, and the mom presumably has been running the fam for quite a while now. I don't see how her slightly disturbing game of house makes sense if she's an agent of the New International Branch, either. If it turns out this speculation is right, it's poor narrative skill on the author's part.