Semi-related: an interesting argument for legalizing bestiality is that what the zoophile does to their animals in their home is done in the agribusiness industry but on scales orders of magnitude larger (and the goal is to get a buck, not get off). When you frame the issue of "should the person down the street be able to rape their dog?" in the context of "should the farm down the street be able to rape hundreds of cows routinely?" things look somewhat different.