St. Thomas on the Causality of Homosexuality

[Uxi]

All human sexuality is ultimately learned behavior.  Note this is distinct from the biological impulse.  Which is itself distinct from the rather absurd modern conception of romantic love being causation for marriage as much as history had it the opposite, be the marriage arranged or whoever the nearest available prospects were to plight their troth, etc.

[Geremia]

All human sexuality is ultimately learned behavior.

So Adam had to learn that Eve complemented him?

Note this is distinct from the biological impulse.

What is an instinct, if not a biological impulse?

[Leonhard]

So Adam had to learn that Eve complemented him?

Yes, he did so the moment he saw her. He probably didn't learn it the same poor way our minds would, but he likely had no knowledge of woman complementing his malehood, before the moment he saw Eve. However the moment he saw her, he knew by divine gifted intuition that she was his complement.

Note this is distinct from the biological impulse.

What is an instinct, if not a biological impulse?

Uxi didn't say that human sexuality was an instinct.