Koisuru Boukun?
This scene? It's not exactly what the OP was describing. http://www.mangago.me/read-manga/koisuru_boukun/mh/v06/c006.5/?av=1
noon, not this one :( the seme was legit bathing with curtains, then the uke came in the bathroom to brush his teeth. It's a fairly new manga and i forgot the name u.u
There's this scene in manga where the uke was brushing teeth and the seme was bathing, then the seme popped up and the uke saw the seme back in the mirror with scratch marks, and bite mark on the neck and got embarrassed. Anyone knows that manga?