Responses
following~ lmfao (づ￣ ³￣)づ
Are you looking for the title? If you are, it's Chapter 5 (I think) of this manga:
http://www.mangago.zone/read-manga/junjou_bitch/
*sorry for late reply thank you!
Story: Uke takes embarrassing photo of seme (I think his underwear was showing) the Uke blackmails into allowing him (Uke) to suck seme's dick. Apparently the Uke had a crush on someone and wanted to repeat a year of school to graduate with this person.