The word anatha-varga is very significant. Natha means “husband,” and a means “without.” A young woman who has no husband is called anatha, meaning “one who is not protected.” As soon as a woman attains the age of puberty, she immediately becomes very much agitated by sexual desire. It is, therefore, the duty of the father to get his daughter married before she attains puberty. Otherwise, she will be very much mortified by not having a husband. Anyone who satisfies her desire for sex at that age becomes a great object of satisfaction. It is a psychological fact that when a woman at the age of puberty meets a man and the man satisfies her sexually, she will love that man for the rest of her life, regardless who he is. Thus so-called love within this material world is nothing but sexual satisfaction.
Source: A.C. Bhaktivedanta Swami Prabhupada (2014 edition), “Srimad Bhagavatam”, Fourth Canto, Chapter 25 – Text 42