Kemono-sama wa Ongaeshi de Haramasetai

Yurito, a playboy who attends a veterinary school, is suffering from the idiosyncratic nature of being "avoided and hated by males", whether they are humans or animals. On the other hand, he has a free-spirited sexual life with women, but these women can't help him get rid of the hot aches in his stomach, so he has to do it himself. One night, when he's masturbating, a big, black beast shows up all of a sudden and licks him there!? On top of that, the beast turns into a human and says, "You saved me a long time ago, and to return the favor, you'll conceive my child." After that, the beast who claims to be a god pushes him down and rubs him in the spot that even he can't reach, and it feels so good...!!!

(Source: Shuusuisha, translated)