[Nigiri Usagi] Sex Suru to SP o Kaifuku Shitekureru Kuro Gyaru Healer [Zenpen] | The Black Gal Healer who Recovers Your SP When You Have SEX [Part 1] [English] [CryptoGreek] [Colorized] [Decensored]
Proof you don't need NTR to "spice things up" if the point of the doujin is to fap to sex scenes. Which means it's the act of NTR people fap to, but will never admit it as to not feel ashamed about their fetish. (as they probably shame others' fetishes anyway)