The chief cause of unhappiness in married life is that people think that marriage is sex attraction, which takes the form of promises and hopes and happiness - a view supported by public opinion and by literature. But marriage cannot cause happiness. Instead, it is always torture, which man has to pay for satisfying his sex urge.
In Tibet there is no marriage, and there is no jealousy, yet we know that marriage is a much higher state. The Tibetans have not known the wonderful enjoyment, the blessing of chastity, the happiness of having a chaste, virtuous wife, or a chaste, virtuous husband. These people cannot feel that. And similarly they do not feel the intense jealousy of the chaste wife or husband, or the misery caused by unfaithfulness on either side, with all the heart-burnings and sorrows which believers in chastity experience. On one side, the latter gain happiness, but on the other, they suffer misery too.