All creatures, big and small, on planet earth have been nurtured, have evolved, and survived through time, creating and building various forms of relationships. This pattern of mutual interaction, for mutual benefit, has existed across all species, irrespective of their location, size, lifestyle or type.
History, culture, religion, and old wives tales have all been contributing factors to establish relationships, the primary of them all being the sexual union for the purpose of procreation and survival of the species. Many relationships, thus initiated, are also guided by superstition, myth, expectations, and servitude. The male, of course, has always been the dominant partner in most relationships across all species.
In Kingdom Animalia, relationships are usually short term and established purely for procreation with minimum emphasis on emotions and staying together. However, some groups do maintain some form of family structure within their tribes in the wild. This also serves as a means of safety and protection for the herd. In some groups its the female who does the hunting while the male takes a break.
Human societies also have a few female dominated groups in South America, Africa, and Asia, closeted within small tribes and castes in remote villages and forests.
Irrespective of the dominant gender, all groups still search for that "soul mate" with whom they think and believe they can spend a lifetime of happiness and contentment. Marriage, is an institution that has been created by religion and culture. While this is now a standard operating procedure across a majority of communities across the globe, there still prevails extra marital relationships, intrigues, and even difficult situations between people in managing their lives. One way of getting out of jail is divorce. However, that facility is not always available in all the prevailing belief systems, even today, in the 21 Century.
Humans meet each other and establish communication and relationships purely based on opportunities that are available to them. One goes to a school or university and makes friends. Some of these early friendships last for long periods of time. Work environments provide another source of contact and making friends. Social clubs, sports, the gym, and other extra curricular activities, bring more opportunities for friendship. Eventually, many of these simple acquaintances lead up to marriage, children, and families.
Thus the "opportunity" is the main factor that provides us with relationship building. If one was born in Japan, the chances are that he or she will start up a relationship with another Japanese and the same will hold good for anyone else born anywhere on our planet. The search for a soul mate does not necessarily conclude that the one you have met and established s relationship with is the best and only available. It is very possible that there may be so many millions of others out there who will fit the bill better than the one at hand.
So, the specific location, date and time, wherever one may have chosen to live or work, or even have been dumped by situations or events to survive, would eventually be the main criteria for meeting someone and establishing a relationship.
Based on this precept would it not then be correct to conclude that we can easily disable a relationship and enable a new one at any given time?