That kink exists in real life. There are unstable women (exactly like the girl in this chapter) who are simply unable to "enjoy" sex unless the act makes them feel defiled and degraded, which they achieve by copulating with the most wretched gutter-scum they can find.
...Well, I'd say it's pretty damn easy to make said fantasy a reality, just go up to them and offer yourself.
And that's exactly what she did.
In a way, they look kinda...scary. Their faces especially the eyes on that last page...