Ex-WWE Star Vader -- My Penis Pic Was Hacked ... Sorry!

So, Vader's naked penis was unleashed on the world Friday via Twitter ... but the ex-WWE superstar says it was a MISTAKE -- and he's pointing the finger at a vengeful ex-girlfriend.

The pic of Vader's junk was quickly removed from his Twitter page shortly after it went public -- and the 60-year-old was quick to explain how it happened.

"I want to apologize to everyone. My ExGirlfriend hacked my account and sent out an inappropriate picture. Please except my apology."