When the father of the girl, without consulting his wishes, confers his own daughter upon a person whom the daughter likes and who reciprocates the girl's sentiments, the form of marriage, O Yudhishthira, is called Gandharva by those versed in the Vedas.
अभिप्रेता च या यस्य तस्मै देया युधिष्ठिर। गान्धर्वमिति तं धर्मं प्राहुर्वेदविदो जनाः॥