Important context on the Tiresias myth
In today's episode, Robert mentions the tale of Tiresias and how Zeus & Hera went to him to settle their orgasm debate, but he doesn't mention why they go to Tiresias.
According to his myths, Tiresias had come across a pair of snakes fucking on the road and used a stick to separate them, and somehow that turned Tiresias into a woman. Tiresias lived as a woman for a number of years, possibly marrying depending on the source, and then coming across another pair of snakes fucking, and struck them apart again, turning back into a man. That is, Tiresias had lived as both a man and a woman.
Hera blinded Tiresias for siding with Zeus, and Zeus gave Tiresias the power of prophecy to compensate, which is how Tiresias wound up advising the Theban royal family later on.
Do I know this because as a young, closeted trans person I was always on the lookout for snakes fucking along the sidewalk? Yes. Also I read Ovid in high school.
(My take on this is that Tiresias was probably intersex or nonbinary, and an imported figure from some of the Near Eastern traditions, where intersex people and gender non-conforming people were often connected with some sort of divination or prophetic ability)