What was King Midas's secret?

In a section of Geoffrey Chaucer’s lengthy poem, The Canterbury Tales, the Wife of Bath digresses from her primary tale for a small anecdote. She claims that she obtained her story from the Roman poet Ovid and, in lines 958-988 of the poem, claims that:

. . . Midas had beneath his long curled hair,Two ass's ears that grew in secret there.

Yes, King Midas had a secret pair of donkey ears! According to the Wife of Bath, Midas’s wife was the only person privy to his secret and had sworn herself to secrecy. Nevertheless, the more she tried to hide her husband’s disfigurement, the more she itched to reveal it. Eventually, unable to cope with the urge to gossip, Midas’s wife made a strange decision. She sprinted to a brook and exposed Midas’s secret to the running water. After this, Midas’s wife felt better and continued to keep Midas’s donkey ears a secret.
The Wife of Bath claims that her story isn’t simply an entertaining tale; it has an important moral:

Here may you see, though for a while we bide,Yet out it must; no secret can we hide.

There you have it. According to the Wife of Bath in Chaucer’s poem The Canterbury Tales, women can never keep a secret! Interestingly though, in Ovid’s version of the story, the wife was not privy to Midas’s secret. In Ovid’s tale, it was his trusted barber who fled to the river to spill the secret. Perhaps women aren’t the only gossips after all! I hope this helps.