so i stumbled upon this description

"1. The uke is the student counsel president and he has to learn a lot, in order to please his father. So, to get "release" ( so to say) he makes other students sleep with him, in exchange for not getting punished for something they did. The manga actually starts with a scene of the uke having sex with a guy in the school toilets. The seme is a common guy, who doesn't seem to take life to serious and does not intend to go to any university after High School, so he doesn't have to learn a lot.
Hmmmm....the uke has black hair and wears glasses ( maybe that helps)"

got me curious and now i wanna read it. anyone know what manga it is?

It should be Ai no Kotoba mo Shiranaide =3

thanks~ do you know anymore mangas where the uke blackmails others for sex? preferably students/in a school setting

How about The Cornered Mouse Dreams of Cheese or Saa Koi ni Ochitamae.

i'll check the second one out sometime. it sounds interesting, thanks