Suggest me some of the smuttiest yaoi you've ever read.

I was recently shocked by the level of smut in this oneshot: http://www.mangago.zone/read-manga/kitsu_ka_nu_shisen/

http://www.mangago.zone/read-manga/window_beyond_window/?av=1
All they do is fuck.

http://www.mangago.zone/read-manga/free_kisses/

Also most of Harada's works are very smutty

Every work of Zariya

This and basically all of its author's works XD http://www.mangago.zone/read-manga/bousou_kareshi/