That would be 'omnisexual', not "trisexual". Trisexual specifically suggests a preference for three 'sexes' (same-sex, opposite-sex and 'other').

Er - ah - and what other category is there besides those three. Are you speaking from experience? Tell me. Maybe there are more experiences to have before I kick the bucket.

Extra terrestrial sex?

Correct - you cannot call Librace gay because he never came out.

Now, on the balance of evidence available on that topic, you may reasonably suspect that Liberace was homosexual, but that would only be speculation on your part.

And "gay" and "homosexual" are entirely different things. These terms are NOT interchangeable.

Secondly, your study of history seems to be rather selective. Homosexuality in ancient Greece (for example) was sternly rebuked and held to be unacceptable. Likewise in ancient Rome. Likewise in 15th century Florence and 19th century Britain.

For your information, in ancient Athens, any proper gentleman who may have sought the sexual favor of an 'ephebian' bloody well had to be a citizen in good standing, with a wife and children. If he didn't he'd be ostracized.

In other words, the ancients understood the term "homosexual" quite clearly and rejected it roundly.

You've apparently got the terms backwards. Anyone who engages in same-sex behavior is understood to have 'homosexual' inclinations.

"Gay" has a socio-cultural meaning beyond that clinical definition.

In other words, "homosexual" is a clinical term. "Gay" is a pop-culture term.

One can be "gay" by US pop-culture standards and never have any 'same-sex' experiences or inclinations at all.

Indeed, if you leave the 'bubble' of the USA, you might find strong resistance to the term "gay" in the homosexual communities. The Brits, for example, generally prefer to use the term "queer" to "gay" - which they consider to be too much of an American political thing.