Alien

just go to mrm? or go to toxic yaoi trope list, I've seen some crazy

It's difficult to find a story that Is a good ready and also has that level of smut.
If you are Just looking for porn i recomend this list https://www.mangago.me/home/mangalist/304690/
Or i could suggest you:

Rabbit ejaculate in 3 seconds
Magical useless gift
Handsome Sales Department is the Ideal Master 02
Male Boob Milk Pheromone
Nanji Ware wo Kouryaku Seyo
Drugless Sex
Blood Bank
Shachiku no Ore ga Ero de Isekai Sukuu tte!? Tadashi Ossan Shika Inai
I put in this list some mangas that, in my opinion, have good plot and also good smut. And mangas that have good smut with a pit of plot
I Hope i could help