“Indra took the form of Gautama to seduce Ahalya, saying to her, ‘I am in the power of Kama. Give me a kiss and so forth.’ But as she was worshipping the gods she told him that he had chosen an inappropriate time. He said, ‘Enough of this talk of what is done and what is not done. You should obey your husband, especially in the matters of sex. Give me an embrace and so forth.’ Then he embraced her and had his pleasure of her, but Gautama knew what had happened by his powers of meditation, and he hurried home and cursed Indra, saying, ‘Since you have acted in this way for the sake of the yoni (female-sexual-organ/vagina), let there be a thousand of them on your body, and let your linga fall.’ Then Gautama went to do tapas, and Indra, full of shame, stood in the water for a long time, praising Devi in her aspect of Indraksi ['Eyes of Indra']. When she offered him a boon he asked to have his deformity cured, but she said, ‘I cannot destroy the evil born of a sage’s curse, but I can do something so that people will not notice it: you will have a thousand eyes in the middle of the yonis (vaginas), and you will have the testicles of a ram.” –

Padma Purana 1:56:15-53.