Jaratkaru

The snake king Vasuki offers his sister, who shares the sage Jaratkaru's name, to be his wife. Jaratkaru accepts, but sets one unbreakable rule: she must never displease him in word or deed, or he will leave her immediately.

Jaratkaru falls asleep at sunset with his head in his wife's lap, forcing her to choose between his anger and his dharma. She wakes him for his prayers, and he, enraged by the perceived insult, carries out his vow to leave her — despite her pregnancy and her family's desperate need for a son.