Note: This story is also available in AO3, which is where I first posted the original version of this story before I decided to rewrite it and make it available on fanfiction, as well.
Chapter Summary: Information of the biology, sexuality, and traits of the genders in this particular omegaverse. I figured it would be better to go ahead and get that out of the way so people can get the gist of it and then dive into the story. And if you reach a part that makes you curious, you can just click away to the first chapter and the information's right there.
Unlike in most verses, alpha, beta, and omega are the primary genders/sexes, while boy or girl are the secondary genders and male and female the secondary sexes. Please remember that gender is mental, while sex is physical, and alpha, beta, and omega can constitute as both due to the fictional physicalities in this verse. Also, one does not "present" at a later age (whatever that means). They are simply born alpha, beta, or omega.
Alphas: A Male alpha's reproductive system is identical to a real-world human male's. However, unlike beta males, alpha males possess a locking bulbus glandis or "knot," a spherical area of erectile tissue at the base of the penis. During intercourse, the tissues swell up and lock sometime after penetration of the male's penis inside the partner, generally about a minute or so before orgasm, though it has been known to happen during or after orgasm, or even immediately after penetration. This is known as "knotting"; this may last up to half an hour or more. The only other mammal known to share this trait with humans is the canine species. Alpha males only have the ability to fertilize. Alpha males are born without foreskin. Unlike beta females or male and female omegas, alpha females only possess one ovary on the left side; in place of their right ovary is a testicle (can't think of what else to call it). This is where their sperm is kept; the sperm is ejaculated through their Skene's gland. Because of this, alpha females only ovulate every two months, as opposed to the standard monthly cycle. Inside their "inner testicle" is the external spermatic, epididymis, and vas deferens. They also possess a prostate (the prostate actually plays a very large part in producing sperm; it also produces calcium, the reason for sperm's milky appearance), seminal vesicles, and bulbourethral glands. However, their "male anatomy" (not counting their prostate) is located in different areas than alpha or beta males (obviously). They also possess a vagina, cervix, a fallopian tube, and a uterus, just like any other female. During intercourse, circular muscles just inside the female alpha's vagina will tighten around the penis significantly, locking the partners together; this is the alpha female's version of a knot. This is known as "locking" or "tying." Because of their unique anatomy, alpha females are able to both bear eggs and fertilize eggs. (No, they cannot fertilize their own eggs.) Because alpha females do not possess a penis, they must manually insert their sperm inside their partner if they are trying for a child; because of this, alpha female's sperm is much more potent than a male's, giving them a better chance at survival. Alpha females are born with a macroclitoris, as well as no clitoral hood; this is how they are told a part from beta or omega females at birth.
Betas: Both beta males and females' reproductive system is identical to that of a real-world human male and female. beta males can only fertilize, while beta females can only bear. Beta females are born without a clitoral hood, but with a regular clitoris. Beta males are born without foreskin, but with no knot. This allows them to be told a part from their alpha and omega counterparts at birth.
Omegas: Omegas, both male and female, possess a female reproductive system. Female omegas possess a normal female physicality, a vagina, clitoris, ovaries, breasts with working mammary glands, etc. Male omegas, like female alphas, possess a rather unique system. Male omegas do not have breasts or a vagina; like other males, they possess a penis (though it tends to be much smaller than their alpha counterparts), a ball sac (also much smaller than an alpha's), and an anus. Their anal canal is where this differs; unlike alpha males, a male omega's anal canal branches off into two different directions, one leading to the intestines and the other leading to the cervix. Because of this, the blood from a male omega's period leaks from their anus. A male omega's anus is naturally elastic in the same way a female's vagina is, allowing for safe intercourse and labors. Male omegas are also capable of breastfeeding despite their lack of breasts; unlike females, whom are capable of retaining and storing their milk, male omegas produce milk during stimulation (as in, they never grow breasts even during or after pregnancy); milk is produced when the nipples are stimulated, but it is not stored, so no breasts. Unlike alpha males, male omegas do not produce sperm; a male omega's penis is the equivalent of a female's clit, and their ball sac the equivalent of a labia; however, their ball sac does produce their natural lubrication - which causes their ejaculation to be clear rather than milky, and their natural lubrication also cleans out their anal canal (in the case of intercourse (a female omegas natural lubrication also keeps their vaginal canal clean in the case of intercourse) or bowel movements) and keeps it clean - and also produces a few hormones, such as their their pregnancy hormones, and a unique mixture of estrogen and testosterone. A male omega's anus possesses many sensitive nerves and is sensitive to pleasurable stimulation in the same way an omega female's vagina is; when aroused, it will swell with blood in the same manner as a vagina, as well. While male omegas do possess prostates, it is different from an alpha's as the prostate normally plays a large role in producing sperm; for male omegas, the prostate helps produce their natural lubricant, as well as estrogen and other hormones unique to male omegas, similar to their ball sac; it is also quite sensitive to sexual stimulation, similar to an alpha's prostate. Male omegas are incapable of impregnating others. Male omegas, like their female counterparts, are incapable of growing facial hair. Male omegas, unlike male alphas, are born with foreskin; this is how male alphas and omegas are told apart at birth. During arousal, the foreskin naturally retracts to beneath the head - similar to how the clitoral hood of a female's clitoris retracts during arousal.
Scents: A human's sense of smell is identical to that of a real-world human's. The only thing abnormal about the sense of smell of humans in this Omegaverse is the ability to pick up on pheromones from other humans. An omega's scent is soft, sweet, and usually smells like different fruits all lumped together, such as a soft mixed berry smell, or a soft, strawberry-watermelon smell. An alpha's scent is usually smooth and dark; normally, they come off smelling earthy, but other scents have been named, such as dark chocolate or caramel. A beta's scent is usually mellow, but not bland; they normally retain a soft, minty or spicy scent, such as cinnamon or cumin.
Relationships: Unlike in other Omegaverses, humans in my particular 'verse do not mate. They behave like real-world humans; they date, marry, have casual sex, etc., etc. The mating is left to the supernatural creatures.
Wolf Hierarchy and Human Genders: Werewolf ranks are capitalized - Alpha, Beta, Omega. Human genders are lower case - alpha, beta, omega. Because a werewolf's human side could be a different gender than their wolf rank, their gender and rank can be hyphenated - omega-Beta, alpha-Beta, beta-Omega, etc. If they are the same gender as their rank, then they are simply referred to as a double Alpha, double Omega, etc.; they may also be simply referred to by their gender/rank.
Heterosexual versus Homosexual: Pretty much any relationship where children cannot be produced is considered a homosexual relationship. Pretty similar to how things in the real world work. So, for example, a male alpha with a male beta would be considered a gay relationship, while a male alpha with a male omega would be considered a straight one; a male alpha with a female alpha would be a straight relationship, while a male omega with a female omega would be the equivalent to a lesbian relationship, just as a female alpha with a female alpha would be a gay one.