Hmmm. A very adament position. These three things are also on my off-limits list but for the sake of arguement, let me ask you this (and not relating to children, no arguement there, we just need to define "child" as age alone is insufficient, noting the age of consent varies by country, including "western" and/or "first world" countries,)...
1) Are you a strict vegetarian? Do your animals consent to be your meat? Your leather? Even your pet? How would beastiality be any different? In fact, it's far less harmful to the animal. My neighbors dog never asked for my consent when he tried to hump my leg... Should the dog be put down for attempted rape?
2) What if someone with a necro-kink made a specific arrangement for his/her corpse to be used sexually after his/her death? That would qualify as consent would it not?