I like the way Rihito is done as a character. It isn't that he doesn't have emotions but rather that they barely show. So even little things like 2 small extra lines on his face have an actual impact.
I think by now it is pretty obvious where this is headed, with him getting some development as well. I mean, I don't think I could ever imagine him calling someone cute or good looking in the past. And he was clearly feeling embarassed as well being given he added in the Tachibana line right after. A lot of people are talking about Noa needing to change for the better but I think Rihito needed to as well (the whole point to me is that them being together gets each other out of their comfort zones) so it's nice to see.