I don't know about you or anyone else, but I honestly don't really wanna see that regardless of where it's shown. If it were Beast people such as a Wolf Man or Cat Woman, or a Holstaurus (Cow Woman), it would be different, but plain ol' animals brings about a bit of a disgusting feeling to my stomach. Like imagine the Main Character doing it with a Dog, it's a Female Dog, but it's still a plain ol' dog, not some kind of Dog Beast woman or Furry.
Good point, but I can hardly imagine someone's gonna watch the MC as a dog, do it to Shadow and get hard and be like "Shadow's so hot", though if someone's like that, I'm not judging them, I'm into some weird stuff too, so to each his/her own. Though imagine if the MC could use his Abilities to turn Shadow into her human form, kind of like how when he was in Prison and you get the choice to do it with this dude as he is or turn him into a Woman first before you do it, that would honestly get me sleeping well knowing that I didn't just obtain a weird bestiality kink.