OK let me break if down for you, first to answer your question, in Australia where I live when a man and a woman live in the same household as domestic partners without marrying (BF/GF living together in the same house), after 1 year it becomes a de facto relationship where each individual posses the same rights as a married couple, for example while you're in a de facto relationship if either partner dies the living person will have a right to inherit whatever is left behind by the dead person (money, property etc.) so does their biological and adopted children.
You seem to go on about people not believing in there love, afraid of committing to one relationship, but this is simply your narrow minded perspective that you've gained from what someone told you or what you've seen in a movie or TV, don't believe everything you see on tele, it portrays western women like nymphos and men to be gigolos; the reality is truthfully far from it. One can argue the opposite of what you're saying, it's because you don't trust your love and has no faith in your partner, that you choose to legally bind them to you through marriage,
in your case when broken could be punishable by death, so who has less faith in their love you or me
Of course I talk about laws marriage and divorce, it's very simple isn't it; it's because marriage is a legal institution, weather you like it or not and *** and love are emotion and when your try to legalise emotions you have to speak of legal stuff :|