http://www.mangago.zone/read-manga/saezuru_tori_wa_habatakanai/mf/v03/c015/14/
that moment Yashiro half-jokingly tell Doumeki how he wont even look at him while giving a hand job/bj..maybe Yashiro realized there`s some progress..-___-
okay so what i think is Yashiro saw Doumeki's coat and since it's a Japanese manga we know how heat plays so much role in these. So Yashiro realizes Doumeki was hot (body temperature) and that means he could be aroused. Maybe Doumeki didn't get hard but still he got aroused and Yashiro realised that. :D

Ok so in the new spoiler, what is the face yashiro's making? Why is he making a face like that? is it because he's looking at doumeki's jacket??? Is it because of the contact case in doumeki's jacket?
Just when they are coming together, this has to happen! ;n; Idk what do you guys think?