Snuff tag might apply, as all the "sex dolls" in this are effectively dead. Taken over by parasites while alive, the parasites consume their memories and kill off the original person, replacing them and using their bodies. Even saying themselves that the original owner of the body is dead after the process is complete.
One could even argue the Zombie tag. In effect, they're a more sophisticated style of zombie used in the Resident Evil games. Of which are often parasites that kill and take over the host. Though the ones in this have much more personality and maintain the body in a "living" state. Instead of decomposing.... (as most of the ones in RE games do, though not all....)
Oyakodon tag should definitely be applied, as the body of both the daughter and mother (while controlled by parasites and not really their own will) take part in multiple threesums.
...either way, very well done Parasite doujin. Not many do it well.
@Chronic Logic The "parasite" is claiming that. The parasite that is controlling the body. The parasite that consumed the memories of the body. The very same parasite that also says multiple times in the doujin that the original owner of the bodies are already dead.
Pretty sure the parasite is just mocking the husband and falsely claiming that it is of her own free will just to mess with him in the video.
@Chronic Logic We see that contradicted later, in the middle of the story. The video in the beginning was just emotional blackmail/torture - to stop the inspector from investigating further.