Yeah, I shouldn't have expected any less from this story. This must be among the funniest confessions in all the manga/anime I've seen. No matter if he did it just to solve this problem (takes it back later) or if he was serious. Although if he backpedals later, it's, of course, hauntingly similar to that sociopath father suddenly leaving their mother, as if it was no big deal. Hina would be hurt by it, no matter how noble his intentions. Although they are so close that maybe she wouldn't really be significantly hurt. More like prickled and able to laugh at it later. Still, I hope he will stick to it! The romance tag must be there for a reason.
In any case, it's weirdly hilarious how I was getting all fired up about analysing the bastard biological father as a textbook narcissist, but then Rei's in all sorts of ways upside down and inside out confession sidetracked my thoughts immediately. The author had it all planned precisely. Excellent writing. Nevertheless, it easy to see the author did read about narcissism (I hope it's not from personal experience), including all that blaming others for his own faults and seeking new love to reinforce his lacking self-respect. Plus all the regular sociopathic behavior, with attempts to manipulate others with no remorse and being unable to sympathise with anyone.