Before he said this:
"The naturalistic fallacy is the fallacy of identifying what is good with what is pleasant, also known as the is-ought fallacy. Please do not use technical terms you do not know what they mean, because it makes you sound like a sophomore."
But then: "The reason why sex should and must be defined as the reproductive act is that anything else is illogical, insane, and, frankly, unhealthy. Humans have allowed new venereal diseases to spread in the modern generation which were unknown in the ancient world, since the pursuit of perverse sexual pleasure, involving the abuse of sexual organs by thrusting them into orifices where nature never intended them to do, is unhealthy, and spreads disease."
First off he give no evidence for the idea that new diseases crop up from not having sex the right way...and now that I read this rape is a sex act as well under this. Second this sort of sexual behavior occurs in nature: https://blogs.scientificamerican.com/observations/why-is-same-sex-sexual-behavior-so-common-in-animals/
Next he should consider the phenomenon of heterosexual AIDS: https://www.reddit.com/r/askgaybros/comments/cc3gnv/how_do_you_prove_that_aids_is_not_a_gay_disease/?
Finally he said sex "should and must" be defined what he wants...which is what the is-ought fallacy is actually defined as: https://en.m.wikipedia.org/wiki/Is%E2%80%93ought_problem
Finally he conflate attraction with sexual behavior.
"The next point will be just as disappointing to you, however: the act of sexual reproduction is the act of sexual reproduction, otherwise known as coitus, whether or not the act culminates in reproducing the young. So, after saying black is white, you say white is not white."
If a sex act doesn't lead into sexual reproduction, then it isn't sexual reproduction.
From here: https://www.scifiwright.com/2014/12/an-open-letter-to-mr-hines/#comment-4384592841
"I do not actually believe you do not know the basics of biology.
""Why must a sex act be defined as being able to lead into reproduction?""
For the same reason twice two is defined as being equal to four: because reality consists of those things which are as they are despite whatever desire we have , no matter how strong, that they be another way.
When what a man says is the way it is, he speaks truth. When he what he thinks is as he thinks, his thought are truthful. When he things and says things that are not as he thinks and says, he lives in hallucination and he speaks nonsense. He lives a life of constant frustration and, all too often, constant fear and hate: because truth is his enemy, the one foe he can never escape.
That is the price you pay for adopting beliefs such as your, sir. Your beliefs are based on sentimental emotion, not on fact. Your words are elliptical and nonsensical, unrelated to real things. The disjointed and broken way you write sentence fragments shows no particular skill at thinking clearly or writing clearly. This may be related to that."
Again when asked why he relies on circular logic. He is right because he is right and refuses to define it.