But that's the whole point though? It's been established early on that the only reason she did all this was with the intention to leech off of him so it's pretty in character for her to be utterly shameless and materialistic, otherwise she wouldn't be there to begin with. The ML himself let's her act that way knowing she's some rando lady pretending to be his wife and mooching on his wealth. Even the FL said that he could easily kill her or kick her out if he wanted, but the ML was the one who decided to let her be despite that fact so that's kinda on him (he even told her that she could continue staying at his place if she had nowhere else to go).
