SB 10.1.35

Kaṁsa was driving the chariot and controlling the reins with his left hand, but as soon as he heard the omen that his sister’s eighth child would kill him, he gave up the reins, caught hold of his sister’s hair, and with his right hand took up a sword to kill her. Before, he had been so affectionate that he was acting as his sister’s chariot driver, but as soon as he heard that his self-interest or his life was at risk, he forgot all affection for her and immediately became a great enemy. This is the nature of demons. No one should trust a demon, despite any amount of affection. Aside from this, a king, a politician or a woman cannot be trusted, since they can do anything abominable for their personal interest. Cāṇakya Paṇḍita therefore says, viśvāso naiva kartavyaḥ strīṣu rāja-kuleṣu ca.