Sex, Gender, and Sexuality
Given that Siderea is quite a bit different from Earth and most similar planets, it comes as little surprise that they view things like gender and sexuality much differently than other planets. With the lineup of creator gods, the variety in the 15 races, and the prevalence of magic, it's only natural that Sidereans are far more open-minded, with their views on things at times confusing those who come to visit.
Sex
There are 4 sexes among the Siderean races, based on the polarities of the zodiac signs:
- Positive: Capable of impregnating others.
- Negative: Capable of being impregnated.
- Neutral: Intersex individuals or those of races who inherently have the equipment for both roles (Virgos, Araneans).
- Variable: Races who are capable of having whatever they please just as part of their natural biological capabilities (Geminis, Libras, Aquarians, Pisceans, Cetans) without having to put in much effort to change.
Any given zodiac is capable of boning any of the others without much trouble (although you might need to be... careful... in the case of like, hot Leo on Cetus action) due to the sexes of each zodiac all roughly matching up with one another.
However, only those of the same or "adjacent" zodiac are capable of reproducing. For instance, an Aries can breed with other Ariens as well as Taureans and Pisceans - creating Aureans and Pirieans - but cannot breed with Cancerians or Capricorns. Ophiuchi and Cetans, being the outliers of the zodiac, can only breed with themselves and each other. As for Araneans... they're complicated. More or less, Araneans can breed with any other zodiac including each other.
While sex is associated with secondary sexual characteristics like in humans, it's to something of a lesser degree and rather arbitrary. In Siderean culture, the body is valued but only in the sense that it's a vessel for the self-expression of the soul; it's an avatar for the mind that inhabits it, thus it should be changed freely to reflect said mind's preferences at any given time. Combined with how easy it is to make such minor changes to one's body with the help of a competent magician, one's appearance does little to indicate one's sex and one's sex - especially what it was at birth - isn't considered particularly relevant to anything other than boning.
Gender
Given the vague, mostly aesthetic attachment to gender at best displayed by the creators combined with the meaninglessness of one's sex, it's probably not much of a shock to say that Siderea doesn't have much of a gender binary. Plenty of Sidereans do still identify as male or female - the terms being something like holdovers that leaked in from the creators and tales of the outside world - but those who identify as male or female are no more or less common than those who identify as agender, genderfluid, etc.
Sex, pronouns, and presentation are considered completely distinct from gender identity, thus Sidereans tend not to make assumptions about people and are confused when offworlders do. Something interesting about them, however, is that they don't need to make assumptions.
Perhaps due to the levels of prima materia and anima mundi present within Sidereans and the planet itself, Sidereans have an instant sense of how those around them prefer to be referred. This tends to catch offworlders off-guard, as Sidereans will tend to use the right pronouns for them when they haven't even so much as given them their name. Sidereans who head off-planet tend to have this ability weakened elsewhere, giving credence to the theory of Siderea itself being ludicrously magical enough to enable it, but tend to still have a better sense of things than most.
She/her, he/him, and they/them are the most common sets of pronouns, somewhat associated with femininity, masculinity, and androgyny like on Earth but not to the extent that anyone finds it strange when a woman goes by he/him or someone likes every pronoun. Neopronouns exist and are easily identified thanks to Pronoun Aura:tm:, but aren't quite as common (not that it prompts anyone to devalue them). Like sex, gender isn't considered important information to Sidereans, so you're not gonna see it on like a driver's license or whatever.
Sexuality
Given Siderea's stance on gender and sex, for the umpteenth time today there are no surprises: Siderea is very much not a heteronormative society. Being pan is the "default" and it tends to be unusual for Sidereans' attraction to be based on (to them, arbitrary and ethereal) things like gender, though not to the extent that non-pan Sidereans are discriminated against or otherwise singled out.
Likewise, monogamous relationships aren't uncommon but there isn't a societal norm of only loving one person, nor are relationships stereotypically defined by the need to marry and have children. Sidereans are free-loving folk, though that isn't to say that there aren't plenty of people in monogamous relationships - or those who aren't interested in relationships at all! Overall, it's less that Siderea's a planet of furry sluts or something and more that they approach orientation and relationships more casually and view them in a more relaxed fashion than your standard Earthling.
This also means the subject of sex is brought up more nonchalantly, at least from the perspective of offworlders. Things that an offworlder might think are frisky aren't really seen as sexual by Sidereans, and some things that are sexual but extraordinarily bizarre by offworld standards are very normal on Siderea. Like if you try to kinkshame that hot Leo on Cetus action they'd just be like "wtf is wrong with you, why are you being racist???" What's so horny about selling Cancer eggs and Taurus milk? It's natural resources, bro, you tellin' me you don't sell yours? What do you mean you don't? Wtf is capitalism? That sounds terrible. Maybe you should have a Libra put their soul in your body and hijack it and turn it into a much cooler species and then put their soul back, your planet doesn't sound very fun. :/
That's a broad overview, of course, with different people and places have different values. Overall you're never going to find a place on Siderea that has values as restrictive as Earth's, but some places are more open and experimentative (shut up firefox it's a word to me!!) than others. Dschubba, for instance, is Dschubba, and devout followers of the Great Fade tend to have views as chaotic and free as the Great Fade herself. Cancerians, meanwhile, have a reputation for being more serious about relationships, and Leos tend to be very concerned about the opinions of their pride when it comes to things like changing themselves or falling in love.
Despite all this, they do find offworld views charming at times and find the pride they take in their identities fascinating. In Entireties where Siderea's mingled with offworlders more often there tend to be more labels around and merch to show off said labels, though it's sort of more a fashion thing if anything. They don't take labels too seriously since Sidereans tend to find them restrictive, but they find them fun to try on every now and then.