Lady Gaga Lady Gaga

Lady Gaga says her song "Swine" is about her being a victim of sexual assault at age 19.

In an interview with Howard Stern on his radio show Tuesday, Gaga says she was raped by a man 20 years her senior who was a record producer. "It didn't affect me as much right after as it did about four or five years later," she told Stern. "It hit me so hard."

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The singer also explained that her performance of "Swine" at SXSW — which featured her riding a mechanical bull and getting paint vomited on her by a performance artist — was an act of retaliation.

"I said to myself, I want to sing this song while I'm ripping hard on a drum kit, and then I want to get on a mechanical bull — which is probably one of the most demoralizing things that you can put a female on, in her underwear — and I want this chick to throw up on me in front of the world, so that I can tell them, 'You know what? You could never, ever degrade me as much as I can degrade myself, and look how beautiful it is when I do,'" she said.

Gaga, 28, says she never confronted her attacker and that she didn't initially realize that what she experienced was rape. "I saw him one time in a store and I was paralyzed by fear," she said. "It wasn't until I was a little bit older that I went, 'Wow, that was really messed up.'"

Listen to a portion of her interview here: