The Zeta do not marry in the same sense that humans do. We, in the Service-to-Others, do not have an institution such as marriage, which is in our opinion a form of bondage, however willingly it may be entered into. If one examines the human institution of marriage for its true purposes, and how those purposes are accomplished in our society, one can see why we are not in need of such an institution. Caring for children, the most often defended rationale for marriage, does not need to be mandated, as all children are cared for by all, and enthusiastically. Compensating the dependent partner, usually the wife, who may give decades of devotion only to be cast aside for a younger model, is another rationale. In our society, no members need fear being rejected. Maintenance is guaranteed, and at the same level for all. Sexual ownership, the complete possession of the object, is seldom acknowledged as the reason for the marriage rites, but especially in highly conservative societies women are brokered openly. This has no parallel in our society, where ownership of the other does not exist.
The institution of marriage is also relied upon in human society so responsibilities can be parsed out. Uncle Joe has nowhere to go, is now blind and deaf, so the family decides he should move in with his niece as she has married well and lives in a large house with lots of room. Her husband may protest, but as he is stuck in the marriage he will eventually give in to stop the guilt trips. Again, in our society, Uncle Joe would not have been desperate in the first place. And finally, humans undergo the ritual and wear the rings so that others will understand fully that they desire to be together. Let there be no confusion, they are bonded. Just look at the ring finger, where they are making their statement.
In our society each Zeta is free, and where there is much bonding there is no bondage. Where humans might consider this a return to the 60's, where free love was the cry and promiscuity the rule, the opposite in fact happens. When not constrained by rules, and given the focus of true service to others, promiscuity does not emerge. Promiscuity most often is a reaction to oppression. Should one doubt this, just check out a group of Catholic boys out from under the nun's thumb. Lock up the girls! Not having the rules, we skip the resentment and rebellion. Casual or promiscuous sex can also happen in human society because the sex drive is strong and the individual focused on the self. After all, masturbation can eliminate the itch, so why pass around infection and create unwanted pregnancies if one is thinking about the other? Sexual concourse should be considerate and not undertaken in haste, and is most fulfilling in this context. Therefore, where we have less bondage, we have more true bonding. And yes, the Zetas do have sex, and pair, even while not procreating through sex at this time.