When you hear “Sappho” or “Sapphic”, what do you think? Lesbians, right? After all, the word “lesbian” means what it does because Sappho lived on the island of Lesbos. For those who are hazy over who Sappho was, she was an ancient Greek poet widely credited as being the first recorded lesbian. She wrote erotic poetry to and about women; hauntingly beautiful even in its English translations. Plato described her as “the tenth Muse”.
Sappho also wrote erotic poetry to and about men, and from the little we know of her life we believe that she had at least one great love affair with a man. That’s right, Sappho was bisexual.
The most famous “lesbian” in history was actually bisexual. If we’re going to talk about bi erasure, I think that might be an important case right there.

Fucknobiphobia: I didn’t know that, but I can’t say I’m surprised. Ugh.

Really, almost nothing is known about Sappho, so we definitely don’t know whether she was gay or bi. What erotic poetry did she write about men? I mean, we also don’t know which of her poems are autobiographical–they’re all fragments, plus she wrote poems for people’s weddings. And if the “great love affair” is the legend where she threw herself off the cliff, a) that is very likely not factual and could very well be a story that tried to erase her love of women and b) it could be a different Sappho–apparently there were two Sapphos of Lesbos, both of whom played the lyre. We definitely don’t know whether Sappho was a lesbian, but I wouldn’t say that we know she was bisexual either. We know very, very little about her. She is more myth than historical figure.

Edited to add: Here are quotes from the Wikipedia article, so there are some sources here

“The Suda is alone in claiming that Sappho was married to a "very wealthy man called Cercylas, who traded from Andros” and that he was Cleïs’ father. This tradition may have been invented by the comic poets as a witticism, as the name of the purported husband means “Penis, from Men’s Island.”^“

”A tradition going back at least to Menander (Fr. 258 K) suggested that Sappho killed herself by jumping off the Leucadian cliffs for love of Phaon, a ferryman. This is regarded as unhistorical by modern scholars, perhaps invented by the comic poets or originating from a misreading of a first-person reference in a non-biographical poem.^[18] The legend may have resulted in part from a desire to assert Sappho as heterosexual.^[19]“