One of the most powerful motivating factors of technology, as well as humanity, is sex. Pornography has driven cutting-edge technology for years the VCR, the Internet, multimedia CD-ROMs and will continue to do so into the era of Shadowrun. This is an area that FASA understandably has to be careful of, in order to avoid shocking the wrong people, but here on the Internet we can take risks that a professional organization cant. :-)
The Matrix, just like the Internet of the 1990s, will have a considerable amount of bandwidth devoted to pornography. In the era of Shadowrun, the capacity for full-sensory interactive experiences will fuel a vast industry. Why go out and meet real people with all their blemishes in the real world when you can do so as a stylized avatar, without ever worrying about exposing your physical form to anything from social diseases to social ridicule? Many deckers may even meet and marry in the Matrix without ever seeing each other in the flesh.
Part of the services of developing an icon will include hooking a person up to the electrodes of a simsense recorder (since only a truly obsessive person would get a simsense rig implanted just for such a purpose) in order to map their sensorium, so they can feel like they are there personally, rather than using a default set of sensations. Some other folk will use simsense responses borrowed from their favorite star, or have bizarre combinations of synthesized sensation created for experimental, artistic purposes. Such a sensory mapping could be very useful in tailoring a synthetic experience for a person for interrogation purposes (think Mission Impossible), and shadowrunners might be dispatched to extract a copy of one from the cyberdeck of a spy who gets their jollies anonymously in the Matrix... or substitute one that incorporates the features of SOTA psychotropic IC at very vulnerable moments.
A common marital problem could be that people have become so used to the artificial highs of virtual sex that the real thing loses meaning for people. This might not just happen to shut-ins who never date in the physical world the problem could also arise for a couple having a long-distance relationship, getting physical via the Matrix. This could get especially bad if theyre using illegal BTL-level chat rooms.
The modern world of sex-change operations, penis enlargement surgery, and so on will still be there in Shadowrun. Cybernetic versions of sexual equipment should be available for those who have had traumatic accidents and those who wish to change sex. Without a doubt, there will also be those who go the route of organ transplants possibly taking on a Type O organ from a different metatype, or even having one run up as bioware with a few modifications. (Some people may go about a sex-change operation by having a chromosome altered in the creation of bioware, and the resulting organs and glands swapped in in an operation.) Note that this should be able to create true sex changes: a woman changed into a man through bioware should be able to sire children, and a man changed into a woman should be able to bear them. (This may make for interesting shadowrunning possibilities: a man who sires only daughters may have one turned into a son to inherit or make an alliance with another family, or an investigation could reveal that a mans wife and mother of his children didnt start out as a female...)
Sexual cyberware will have a variety of possibilities for intrigue, given the possibilities demonstrated by cybereye weapons. Ill leave the details to your gamemaster. Aside from organ transplants, complete skin replacement might also be popular for someone attempting to attract another metatype.
Shadowruns medical technology seems easily capable of providing birth control implants for men and women; a common implant for women would place their bodies into a state like a trained athletes, suppressing menstruation in addition to fertility. (This would even be done for health reasons, as studies in the modern era suggest that women are living much longer than ever before and their bodies dont seem to be designed to go through the stress of menstruation as many times as they are; women in the Shadowrun era might only menstruate once or twice a year.)
One of the reasons that social functions for just mages might exist is that astral perception could make a big difference to sex. Some mages might prefer to be astrally perceiving when making love, because of the heightened emotional transmission, and might prefer to have a partner with the same capabilities.
Astral travel offers many possibilities. One might also find mages with long-distance relationships commuting to sequestered spots on the astral plane to get together, if the transit time from one to the other is too long for their Essence ratings. Initiates might decide to join a low-rating quest simultaneously to get some private time together without all that tedious travel time.
With such practices becoming more common as mages proliferate, some places may turn into astral hangouts perhaps selected for an aesthetically pleasing background count. If your campaign allows people to enter the metaplanes explicitly to get to a meeting place (defining a quest as to reach the place where everyone else is going to hang out and meeting up at the Citadel not explicitly forbidden by the rule in the Grimoire that specifies that you cant have someone join up in the middle of an Astral Quest), there may even be singles bars for the Initiated deep in the metaplanes.
Assensing also has other uses: it should be possible for a good assensor to detect pregnancy in a womans aura as early as one month of gestation, if not sooner. Depending on campaign flavor, a fetus aura may show independently (either through the mother or using a fiber optic scope) at some point probably by the third trimester and could provide additional fuel for debates about abortion.
Naturally, there will be Health and Manipulation spells for dealing with all manner of sexual matters (and probably a few Detections and Illusions as well). Transformation manipulations offer any number of interesting possibilities, and the effect of having children when one or more partners is involved in shapeshifting is a GM call. (A male mage with a spell locked sex change spell might successfully carry a child to term, though having the lock switched off at the wrong time might cause some very nasty things to happen in their abdomen. A GM may, of course, rule that magics transformative powers dont extend to reproduction.)
Naturally, some tacky questions will come up, such as the possibility of Trolls being sexually compatible or not with other metatypes, and what happens when two different metatypes have children. The alt.sex FAQ suggests that the average size is 15cm (6) and 90% fall into the range of 13cm - 18cm. Assuming linear scaling, the average Troll will clock in at a little under 25cm (10), which is within the realm of human variation, and should make sex between a male Troll and any female metatype larger than a Dwarf more practical than the current-day human practice of fisting. (Still, Troll rapists will be a particularly nasty sort of criminal.) I assume that relationships between people of different metatypes should all be possible, but will often raise eyebrows and create alternative cultures.
The rules about different metatypes procreating are given at the beginning of the section describing the metatypes in Shadowrun 2. Humans and metahumans should be unable to procreate with dragons, free spirits, sasquatches, and so on without the aid of magic or genetic engineering. (Whether the magic is as easy as a shapeshift spell should be a GM call... but if you call it so, therell be plenty of such bizarre individuals turning up on Geraldos 2056 equivalent and you get to deal with your players wanting to play such an offspring...)