Yàoi sex slave ... Rape anything like rape I need it but has to be yaoi

http://myreadingmanga.info/tag/rape/
http://myreadingmanga.info/tag/gangrape/

http://www.mangago.me/read-manga/rakuen_no_ori/ it has that vibe xD

http://www.mangago.me/read-manga/no_99_ningen_omocha/ the boy was brought to his master as a gift i think

http://www.mangago.me/read-manga/mob_for_jack/ they kinda use him like that
http://www.mangago.me/read-manga/pet_keiyaku/ sex pet
http://www.mangago.me/read-manga/void_zariya_ranmaru/

this are the only ones i could remember that are similar to what you are looking for

http://www.mangago.me/read-manga/dakaretai_otoko_ichii_ni_odosarete_imasu/
http://www.mangago.me/read-manga/unbalance_na_netsu/
http://www.mangago.me/read-manga/gintama_dj_mienai_kusari/
http://www.mangago.me/read-manga/ao_no_exorcist_dj_fill_kill_reverse_my_moment/
http://www.mangago.me/read-manga/gintama_dj_kabe/