If you know you are always going to be in love with a certain person, is it selfish and unfair to get into relationships with other people?

All men and women know that there is a single mate who is destined for them, and whose name is written alongside your own, etched in ancient runes on the ribs of the gods below, where their skeletons slumber, awaiting the day when they will rise from their graves and devour the world. This is no secret, and it is right and good that you should seek out that mate, heeding the whispered advice which comes from the painted skulls of your ancestors where they are kept in the deepest reaches of your family's cave. To deny this is foolishness and heresy, and one who did so would be fit only to mate with dogs, and eat only maggots and flies, as the old saying goes.

But love is like war. One must best many partners in practice for the real thing. Bedding them hones your instincts and strengthens your loins, infusing in them the fire and stone which you will need to match the terrible fury of your intended one's lovemaking when at last your bodies come together as one to produce the offspring which will care for you in your dotage when you are old men and women of thirty, your bodies crumbling to dust and minds gone to madness and the terror of immanent death.

Do not feel ashamed that you practice the art of love; know that your mate is doing likewise, and that you shame both you and they if you come to them unprepared and unpracticed when you copulate for the first time together in the view of your tribe as they dance in a circle around you, singing your wedding-song and cheer your act of love-making. To do so will produce weak children, prone to possession by devils and evil spirits, who will steal your breath in your sleep, to the eternal shame of your tribe.