Tbh, if Suiren realize hes not going to the rooftop but is eating with Koharu she'll get the worst impression.
Hes being a pain for a while now. Suiren was so happy at the fireworks but after that he been only showing the worst signs.
About Koharu... she should had given up the last time she cried already. Hopefully she'll give up for real. Not that it makes any difference.