>>935857728Well I wouldn't try to whip up some emotional justification for it. Just an absence of harm.
If she gets on all fours and the dog decides to do its own thing, it's not like you're beating it with a cane. With a male human I could at least see how it could be physically harmful to be forcing an orifice not designed for this.
This level of freakout over it seems weird when some actual predatory or domination focused stuff is normalized in society.