Yaoi or BL where the top is smaller than the bottom? Idk I've seen too many generic storie...

http://www.mangago.zone/read-manga/shigekikei_my_hero/
http://www.mangago.zone/read-manga/yondaime_ooyamato_tatsuyuki/
http://www.mangago.zone/read-manga/joou_to_shitateya/
http://www.mangago.zone/read-manga/usagi_chan_doshikori_moushiagemasu/

There is all the yaoi dynamics in this one, so don't stop at the first chapter only ! =
http://www.mangago.zone/read-manga/the_secret_case_files_of_the_cafe_april/

http://www.mangago.zone/tag/big%20uke/

http://www.mangago.zone/tag/small%20seme/