It's about how the seme is obsesse with the uke and he blackmails him after seeing him do something?(im not sure) But there's a scene in the beginning where he walks past the uke and takes a whiff of him. (and i think they both met a few years back but im not sure)
Yaoi manga about two introverts who meet on the train and seme is accused as being a pervert but uke saves him and the story goes on from there. The seme also has a lot of candy.
im looking for a yaoi where the seme drinks the uke's spit while having sex. Other things that happens in the manga is that the uke pushes the seme when he gets too close and he twists his ankle or something like that.
http://www.mangago.zone/read-manga/mujintou_ni_motte_iku_nara/