Yeah, I even felt weird using the word spectrum. I'm visualizing a 3-dimensional gradient where each individual point in space reflects a unique sexuality. It's about as unique to you as your fingerprint. It's insane to me that we had such black and white categories for so much of our history.

There are actually different models of talking about sexuallity. The one most common that you know where there's stuff like gay, lesbian, bi... But when you have trans folks that doesn't nessisarily give much credence to genital preferences. It's more a reference to the cultural gender expectations. A cis man and a pre-medical trans man is still gay where a cis man and a trans woman in the same situation is straight... But when you are non-binary this model doesn't serve because if I am culturally neither male or female is me liking a specific presentation gay or straight? If you're defaulting to what my body type is then neither is correct. I am not pan or bi because I don't like both and I am not straight or gay because those things frame relationships between physical sexes not fitting neatly into the changing cultural landscape of gender.

The other less used model just describes what someone finds sexy. A gynophile is attracted to feminine presentation, androphiles like the masculine, Skoliophiles are into non-binary people and ambiphiles like all.

It is a little 4D chess but it's easier to pick up when you don't have to account for old rules.

It's an n-dimensional spectra, but I'm not really sure what n is in this case. It's at least two, with one dimension being masculine/feminine and the other being penis/vagina, but there are way more things to sexual preference than that. We need one for dominant/submissive, multiple dimensions for hair color, maybe age, and all kinds of other factors. Every person will have a range of preference for all of these, and they aren't just the far ends.

If gay would mean many things, the word would be useless.

Yeah, totally. I mean, that's definitely why there aren't any words at all in the entire English language that have more than one strictly defined meaning, and that meaning has never, ever changed.

Love is multiple things and is still meaningful for us.

Theoretically I can see somebody not being attracted to guys, as in masculine people, or just males, but still being turned on by penises as we see in OP's example. That person might not call themselves gay since they wouldn't want to be in a relationship with any guys, but might be interested in a hookup with a trans woman who still had their dick.

Maybe their is some nuance in what being gay is or there is room for another descriptor for this phenomenon.

Edit: reading below, this person might be hetero-romantic and homo-sexual.