Responses
Probably because he was super used to that life. Until it hit him in the face it is natural at that point for him to act like it's no big deal. Although when it comes to no personality I can see why you think that. Maybe he's just a naturally partially empty sounding person.
Mmm didn't like it much. Seme has no personality and didn't seem to feel anything for MC at all until the very last chapter （￣へ￣）