Someone commented last chapter that he and Ruby used to be a couple. Did... The author forget about that? When did this happen? Even in the flashbacks all she does is insult him. Why would he say yes to a relationship like that? Why would she request one if she always looked down on him like that? Unless there was a point where they actually did enjoy each other's company in between their childhood and current day.
This seems like one of those stories that bring annoying people from both sides of the spectrum when they deem the "other side" as an idiot with either a saviour complex and/or a psychopathic streak.