hentai where the protagonist is dominated and has anal sex with the dominatrix

[hprota]

I can't remember the name of this hentai. But I remember that the protagonist is crazy about a girl who dominates and humiliates him. At a certain point she lets him have sex with her, however, he chooses to have anal sex with her instead of penetrating her vagina, because he doesn't consider himself worthy of having real sex with her. She says that he is a pervert or degenerate (something like that) for choosing her ass, however, she likes it.