hmm, this sure twists my insides... that was intense... also, sure that guy have not done the best of choices, but given those choices he has actually tried and acted in the best manners possible, maybe not the part about lying and twisting their relationship. However, the daughter sure is over the line, it's fine to not like something but without them having done anything concrete other than hangout, ESPECIALLY because it all started with her, she shouldn't have behaved in that manner without clearing up things. The guy sure is pushover though being dragged around everywhere leading to where he is now XD
Another thing that irks me is how she behaves towards her father, pre-rumour confirmation, where given how hard the guy is working and giving his best to advance his career to support the family, only him and her now, and there's no acknowledgement but instead actually condemning him for it.
PS. I know the culture in Japan is more strict towards this kind of behavior, just inputting personal thoughts on the characters