"Family values," of course, is a purposefully evasive and loaded buzzword. But it is pretty clear what we usually mean by it. That's a number of disquieting obligations we all have,
"Family values" would urge us (grown-ups) to set up our own emotional, psychological, and expressive priorities towards meeting the needs of a single (legally recognized) marital partner for an adult lifetime. I become a man I give up baby-play and childish things, like sexual fantasies. Furthermore, in most cases, it means orienting one's life towards having and raising one's children. It means giving up certain adult pleasures and pursuits because their fallout can make the world hostile to children. We may not safely satiate ourselves and let the cake batter trickle down to the kids.
At least, this is how the communal moralist sees "family values." In practice, certain observations stand out.
For instance, remember the old paradigm of wedding night consummation, and no sexual intercourse before marriage. The marriage sacrament was supposed to change especially the man into a new self. Stable marriage and parenthood were universally accepted preemptive personal goals. A young man was expected to learn these values from a chosen woman and then internalize them; the catalyst was raw heterosexual attraction. His sense of "masculinity" was to become a devotion of his own sense of action and doman. The mere mention of alternative possibilities, especially the acceptance of "gay lifestyles" (or, for some people, even toleration) was considered a fatal distraction. Pornography was considered toxic, since it would undermine the ability of the man to feel interested over the lifetime of an aging wife. Much of this view comes from earlier periods of our history when the survival of "ordered liberty" seemed to depend on fidelity of most men and women to their biological gender roles.
The other thing that stands is more economic. The entrepreneurial and "Darwinian" workplace is sometimes disparately hard on middle-income families with children, in comparison to singles. Consider the way two-income families fed on themselves and bid up housing prices for everyone! So the conservatives pass per-child tax credits and even propose at least a voluntary revival of the "family wage." Will conservatives (and even some sloppy liberals) admit openly that they want to force singles to help subsidize other people's children?
The libertarian's answer to all this moralizing is simple: get the government out of marriage. Let any group of competent adults consent to any contract they want, and let the tort system enforce it. That's all.
Other gays quite properly recognize the social benefits of marriage (as well as economic privileges and preferences). Gays often do make good parents; but even for the majority who are not, the benefits of a lifelong stable relationship, in providing someone one matters to and in providing a psychological safety net, are obvious. Hence, we have the gay-marriage debate and knee-jerk "Defense of Marriage Act." Should Federal spousal benefits be affected by state law? The best solution (regardless of all the litigation starting in Hawaii) is that marriage be offered (to a same or opposite sex couple) only when there is a dependent in the household, or when the couple is able to make a binding, for-life commitment.