Vraja is the land of prema. The prema present in Vraja is impossible in Mathurā. Kṛṣṇa will not see those in Mathurā like they are His beloveds. He will see they are sisters, relatives, or the wives of others. He will never see them as beloveds. He will view them with maryādā—regulative principles. But in Vraja, Kṛṣṇa’s vision is that of parakīya-bhāva, paramour love and affection. Svakīya-bhāva is not possible in Vraja.
Srila Gurudeva - March 31, 1998 Mathurā