Story of Surya Devta in Hinduism

1. Surya Devta raped Kunti

📚Devi Bhagavatam 2.6.13-35
Sūta then said :– “O Dvija! While Sūrasena’s daughter Kunti was a virgin girl, the king Kuntibhoja asked for Kunti that she might become her girl and Sūrasena gave her to the king Kuntibhoja who brought up this beautifully smiling girl. He put to her the service of Agni of Agnihotra. Once, on an occassion, Durvāsā Muni, engaged in the vow, lasting for four months, came there; Kunti served him during that period; the Muni became greatly pleased and gave her a very auspicious, mantra, by virtue of which any Deva, when called upon by that mantra will come to Kunti and satisfy her desires. When the Muni went away, Kunti, remaining in her house, wanted to test the accuracy of the mantra and asked within herself  “What Devatā to call upon.” Seeing the God Sūrya had arisen in the sky, Kunti uttered the Mantra and invoked him. The Sun, then, assuming an excellent human form, came down from the Heavens and appeared before Kunti in the same room. Seeing the Deva Sun, Kunti became greatly surprised and began to shudder and instantly became endowed with the inherent natural quality of passion (had menstruation). The beautiful-eyed Kunti, with folded palm; spoke to Sūrya Deva standing before :– “I am highly pleased to-day seeing Thy form; now go back to Thy sphere.” Sūrya Deva said :– “O Kunti! What for you called me, by virtue of the Mantra? Calling me, why do you not worship me, standing before you? O beautiful blue one! Seeing you, I have become passionate; so come to me. By means of the mantra, you have made me your subservient so take me for intercourse.” Hearing this, Kunti said :– “O Witness of all! O knower of Dharma! You know that I am a virgin girl. O Suvrata! I bow down to you; I am a family daughter; so do not speak ill to me.” Sūrya then said :– “If I go away in vain, I will be an object of great shame, and, no doubt, will be laughed amongst the gods; So, O Kunti! If you do not satisfy me, I will immediately curse you and the Brāhmin who has given you this mantra. O Beautiful one! If you satisfy me, your virginity will remain; no body will come to know and there will be born a son to you, exactly like me.” Thus saying Sūrya Deva enjoyed the bashful Kunti, with her mind attracted towards him; He granted her the desired boons and went away. The beautiful Kunti became pregnant and began to remain in a house, under great secrecy. Only the dear nurse knew that; her mother or any other person was quite unaware of the fact. In time, a very beautiful son like the second Sun and Kārtikeya, decked with a lovely Kavaca coat of mail and two ear-rings, was born there. Then the nurse caught hold of the hand of the bashful Kunti and said :– “O Charming one! What care can you possibly have as long as I am living.” Kunti then, placed the son in a box and said :– “O son! What shall I do? Being afraid of shame, I am leaving you, though you are dear to me as my life itself! I am exceedingly fortunate that I am casting aside this all auspicious son. May the attributeless Bhāgavatī Ambikā, the World Mother and the Lady of all, endowed with attributes, protect Thee! May Kātyāyani, the giver of all desires, feed you with Her milk! Alas! I am quitting you, born of Sūrya’s semen in this solitary forest like a vitiated wanton woman. I do not know, when shall I see your lotus like beautiful face, dearest to me like my self. Alas! I never worshipped in my former birth Śivānī, the mother of the three worlds; I never meditated Her lotus like feet, the Giver of all happiness; hence I am so very unfortunate. O Dear son! I must perform great tapasyā to expiate for this terrible sin, that I knowingly commit in relinquishing you in the forest.”  (source)

📚Shrimad Bhagavatam 9.24.33-36📚
As soon as Kunti called for the demigod of the sun, he immediately appeared before her, and she was very much surprised. She told the sun-god, “I was simply examining the effectiveness of this mystic power. I am sorry I have called you unnecessarily. Please return and excuse me.” The sun-god said: O beautiful Prtha, your meeting with the demigods cannot be fruitless. Therefore, let me place my seed in your womb so that you may bear a son. I shall arrange to keep your virginity intact, since you are still an unmarried girl. After saying this, the sun-god discharged his semen into the womb of Prthä and then returned to the celestial kingdom. Immediately thereafter, from Kunti a child was born, who was like a second sun- god. Because Kunti feared people’s criticisms, with great difficulty she had to give up her affection for her child. Unwillingly, she packed the child in a basket and let it float down the waters of the river. O Maharaja Pariksit, your great- grandfather the pious and chivalrous Page King Pändu later married Kunti.”  (source)

2. Surya Devta raped his wife

📚Brahma Purana 4.42-43📚
The lord assumed the form of a horse and approached her as she grazed about fearlessly in the form of a mare. It was in her mouth that he had his sexual intercourse, as she began fidgeting due to her suspicion that he might be a person other than her own husband. She let out the semen of Vivasvat through her nostrils.”  (source)

3. Surya devta had sex with a mare (a female horse)

📚Shiva Purana 5.4.21📚
The sun of fierce rays, deluded by Shiva’s Maya became lustful on seeing a mare and assumed the form of a horse.”  (source)