This excerpt from the Baudhayana Shrauta Sutras, a text associated with the Yajur Veda, describes an interesting story involving a war between the Devas and the Asuras:
When gods and demons fought a great battle, these creatures dispersed in diverse directions; some went to gods; others to demons. Brihaspati was the priest of gods; Ushanas Kavya of demons. Gods passessed Brahman-power. Demons possessed Brahman-power, They fought many battles without decisive victory. Gandharva bearing solar lustre knew what was going to happen. Indra was the paramour of his wife. He said to her, "O thou whose limbs are immortal. do thou ask the Gandharva as to why the gods of demons do not win." "All right" she said to him, "Do thou come tomorrow." He (Gandharva) sported on the sea together with his wife in a golden ship. Indra came. He became a golden ray and stuck on a major part of the ship, Seeing that he had come, he asked him. "O thou with immortal limbs, please say, why gods or demons do not become victorious," "Do not speak loudly," he said. "The ship has ears." "Gods have Brahman-power, demons have Brahman-power," he said. Hearing it Indra took the form of a yellow parrot and flew up. Looking at him, he said, "O Indra, those will win who have yellow (parrot) on their side." He (Indra) went to Aushanasa Kavya and conferred with the daughter of Jayanti and four desire-yielding cows. Instructed, he left the demons and went to the gods. Consequently the gods won the great battle.
Ushanas Kavya is another name for Sukracharya. But my question is, who is the Gandharva whose wife was having an affair with Indra, and who gave Indra a prophecy aboard a golden ship?
Now in the Vedas the word "Gandharva" is most often used as a name for Surya the Sun god, rather than as a name for the race of celestial singers the term most commonly signifies now. And the fact that the Gandharva in this passage is "bearing solar lustre" is more evidence that it's Surya. But did Indra ever have an affair with one of Surya's wives? (I discuss Surya's wives here.)
On a side note, who is the "daughter of Jayanti"?