Tzientai reproduction

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The first two sexes are known as 'first producer' and 'second producer'; they are almost identical, but for the complementary tapering of their protruding genitals (one tapers outwards, the other inwards). The reproductive process begins with the two producer sexes joining, and they pass pre-egg masses between one another. The pre-egg mass takes on DNA from each producer. It's an article of faith that more passes make healthier offspring; pre-eggs that are passed fewer than six times certainly don't tend to develop properly. However, each pass has a chance that the pre-egg will divide, or be absorbed into the parent, so pre-egg masses with twenty or more passes tend to fail as well. This joining is the first step of the reproductive process. The next step can occur within about ten days of the first step; if it doesn't, the pre-egg is typically reabsorbed into the parent.

Strictly speaking, the third sex, or the 'facilitator', is not necessary for reproduction, but reproductive processes that feature a facilitator result in a healthy hatching vastly more often than processes without one. The fourth sex, or 'bearer', is entirely necessary. The second step in the reproductive process involves either a first or second producer implanting the pre-egg masses into the bearer, whose genitals are concave. With only a producer and a bearer, the producer simply places their protruding genitals within the concave genitals of the bearer, and implants any number of eggs. Because the bearer does not naturally lubricate, this is unpleasant for both parties.

(Implanting eggs is a conscious decision, meaning that the Tzientai equivalent of orgasm is not necessary for mating. It's possible for all sexes and considered quite a good thing to encourage, though. Bearers have healthily carried up to six eggs, but a producer who implants more than four eggs at once is considered kind of a selfish jerk.)

The facilitator's genitals are neither concave nor convex, and instead somewhat of an organic mesh around the groin and where the perineum would be on a human. When a facilitator is aroused, they exude a pleasant-smelling goop from their mesh genitals, which also carries some of their DNA. Mating between a producer, a facilitator, and a bearer involves the bearer and producer holding the facilitator from either side, pressing their genitals to the facilitator's, and slowly approaching one another until reaching penetration.

This second step of the reproductive process is the one most eroticised and romanticised by the Tzientai. Coupled with the fact that the facilitator's arousal, with its strong scent, is the most difficult to conceal, and the fact that facilitators have sensitive erogenous zones on their chests and back to encourage their three-way mating, the facilitator sex is the one most sexualised, and consequently the least powerful in society. Soch-Metions, with their "sexism what even is that" culture, tend to find this disgusting.

The bearer holds the eggs within them for ten to eleven solar months. After twelve months, the eggs' growth forces the bearer to lay them, which the bearer is not designed to do alone; while having to lay a single egg is sometimes survivable, any more than that will always, without question, kill the bearer. Forcing pregnant bearers into conditions with no birthers or hatchers is considered an act of torture. Some early and particularly brutal Tzientai societies used it as a form of execution.

When the bearer is ready to birth, the birther gets involved. Naturally. The birther's genitals are, essentially, a group of long, retractible tendrils. The third step of the mating procedure involves the birther's genitals reaching into the bearer's uterus, encouraging the bearer's genitals to widen through the birther's secretions (which, yes, deposit the birther's own DNA; each sex contributes DNA to the offspring, even the facilitator), and drawing the eggs out one at a time. Ideally, the birther deposits the eggs directly into the care of a hatcher, whose genitals are essentially large, encompassing flaps; differently arranged, a hatcher can typically handle as many as three eggs at once, though four is a possibility and five is an outside chance.

The hatcher incubates the eggs within the cowl of their genital flaps, which are somewhat prehensile, allowing them to find where the embryo is pressing at the egg's shell and to either push back or pull open that section of shell. The hatcher's genetic contribution is the lowest, but does still form an appreciable portion of the offspring's DNA. Multiple hatchers can be involved in a single third step of the mating process, which is considered mildly kinky. Eggs laid without a hatcher have about a one percent chance of hatching spontaneously; these "unhatched" are, according to superstition, destined for bad luck and misery. There could be a basis for that, since unhatched Tzientai lack a portion of their genetic material and are prone to ill health.

(The same occurs for Tzientai born without a facilitator in the process. However, while the term "unhatched" invites sympathy, the phrase "So, no facilitator in your birthing, then?" is used much along the lines of "You were dropped on your head as a child, right?" and invites the same kind of fighting.)

Socially, two marital groups tend to form: a two person marriage between a first and second producer; and a three person marriage between a bearer, birther, and hatcher. Either marriage can also include a facilitator. Sometimes, one of each marital group will form a bond for repeated reproductive processes, but this is rarely considered as potent a bond as an individual marital group, and a marriage between all six sexes is considered weird and slightly unwholesome.

Since producers both only bear pre-eggs for less than a month and don't birth children themselves, they have the least burden in the reproductive process. This has led to greater economic success for producers and painfully severe sexual inequality.

Tzientai have their own pronouns for each sex. Translating to Standard, best practices are to use "them" for all six sexes. There are standards for using "he" and "she" - "he" for both producers and birthers, "she" for facilitators, bearers, and hatchers - but it's considered chauvinistic and declasse.