The only big development since their plotline is during Christmas where the President talks (to the bear and Norio) about how Yonekuni hasn't touched him ever since that last time. And it's revealed that Yonekuni is insecure because he feels like the President is actually in love with the version of himself that was 'unconscious'. Yonekuni doesn't believe a guy can fall in love with him since he treated men so badly. Anyway he gets encouragement from his brother and he hugs the president later during the party. (Basically he's committing to having a relationship with President.) They appear a few times after that, being close and leaning on each other, but not as the focus. There's one super short side story where Yonekuni sees a bug bite on President and thought it was 'unconscious' him who did something and got riled up, but nope. And he storms away embarrassed.
Unfortunately like all the other couples that the author wrote, they got pushed to the side for the newer couples. So most of the time they're there looking like...very close friends. Dating but probably not doing anything physically.
I stopped reading a long time ago, but can anyone tell me how the relationship goes between yonekuni and the president, I only remember the first time they got yogether