Liberals & democrats only; what sexualities do you actually consider valid?

The only valid sexualities are those in which someone is drawn to someone of the opposite gender. It matters not their age, race, religion, or even if they are a mannequin or doll. 

I don't really think it's up to me to say what someone else identifies with as valid or not because I'm not the police in these parts. I think most people would use the terms listed for shorthand, and if they want to get really deep into explaining who they are, other terminology exists to help them do so. 

People who are of minority status and don't see themselves reflected in much of the rest of the world go looking for who they are, hence the increasingly specific nomenclature. e.g. one can identify as an *agnostic atheist as opposed to an atheist. People call themselves democratic socialists as opposed to one or the other. 

If I'm going to be in a straight space, I would just say I'm lesbian or queer. If I'm talking to people who know the extended terminology I would say other things like demisexual or something. 

I think arosexual might not fall under your terms. 

Heterosexuality

Homosexuality

Bisexuality

Asexuality

Heterosexuality, Homosexuality, Bisexuality. Trans

That’s it. I have no use for LGBT neologisms and the ever-growing number of genders. 

Some of the new labels are ridiculous. Nobody would need them.

I see them being used only for satire by parody accounts 

Straight, gay, bisexual.

That's it.

There are fetishes or paraphilias but they're not sexualities.

I'm a pretty-free-thinker, minority member, but not a Democrat.  As for my own use, I really don't have much need for terms beyond "straight", "gay/lesbian", and "bi".  And of course I know some folks are asexual, too.  (I don't think of "asexual" as a sexuality, per se.  It belongs on a different taxonomical level.)

Those three terms address only the issue of what sort of plumbing your partners can have.  There are those who would expand this to include other issues...other criteria like the level of romantic attachment your partner must induce, or what gender your partner must feel himself or herself to be.  These things all DO figure into sex, but I feel that sort of expansion could continue until we have terms to describe color of hair and income bracket...and so I've decided that, for me, sexuality is a concept best limited to the simplest and most-widely-applicable criteria.  For the moment, that seems to be "plumbing", so while I'll listen to explanation if someone wants to tell me they are demiromantic homofurrious, I really think just in terms of either boys, or girls, or both.

When you think about it, our sexuality is set up to steer us to appropriate mates.  Our "sexuality" therefore includes a preference for LIVING vs dead, HUMAN vs other species, HEALTHY vs damaged or sick, ADULT vs little kids, STRANGERS vs our own children, parents, or siblings, and also OPPOSITE vs same sex.  As we know, Mother Nature for one reason or another does not always express every bit of that in every individual.  She sometimes flips one or more of those filters.  Which one does she flip the most often?  I'm betting it's the last one.  So THAT'S the one that we should refer to if we want a set of terms to help us pigeonhole most people.

And THAT'S why, for myself, I consider sexuality to be centrally concerned with plumbing, even though I know it involves ALL those creepy criteria, and maybe others besides.  I keep an open mind, though.

i'd say heterosexuality, homosexuality, bisexuality, and asexuality. pansexuality i view as a synonym for bisexuality, but it's also valid in the sense that i respect people who feel this term more closely fits them.

the only other main one i'm really aware of is demisexuality, which describes people only forming a sexual attraction to people they already have a strong emotional bond with. while i do feel this can be a thing, i wouldn't say it counts as a separate sexuality in and of itself; same with gray-ace (mostly asexual but not entirely).

and then uh, i guess conditionally androsexual and gynesexual? mainly in the case of nonbinary people attracted to one of the binary genders, since it wouldn't make sense to call a nonbinary person attracted to men homosexual. i admittedly don't really think of these two labels much, though.