Imagine if we took what Rudy says and replaced "bestiality" with "rape" to get: “The widespread social ban on rape rests on a solid notion of what sex is, and queer theory persuasively argues we simply don't have such a thing. The interdict against rape can only be maintained if we think we always/already know what sex is. And, according to queer theory, we don’t.”

When you phrase it like that it reads more like an argument for why queer theory is wrong than for why rape is okay because everyone knows what constitutes sexual contact