For the past three decades, Weird Al Yankovic has reigned as pop’s king of parody, launching barbs at music’s other royals like a kid with a slingshot. Now he’s returned with a potshot at Lady Gaga, with the tune “Perform This Way,” the lead single from his new album, “Alpocalypse,” out Tuesday.

A fun-house reflection on Gaga’s “Born This Way,” the spoof generated huge attention for Yankovic after the diva’s management told him she didn’t approve of the song. So he released the track on YouTube, where it has since garnered nearly 3 million views. Gaga’s camp, meanwhile, has graciously blessed the song. Speaking to The Post from his home in LA, Yankovic recalls how he got the tune onto his new album.

So what happened with Gaga?

[Usually] I just say “I want to do a parody,” and the artist says yes because of my track record. They know I’m not making fun of them. It’s an homage. [Even] the most hesitant artist only wants to read the lyrics. Gaga was unusual because her manager asked for a finished recording. They were like, “If we don’t hear it, we won’t approve the song.” So I finished it, recorded it, sent it over. Then her manager said no.

Were you mad?

I didn’t understand. I put in a lot of work. I wanted people to hear what I’d just spent the last month on, so I threw it on YouTube. Everyone loved it and wrote comments like “How can Lady Gaga do this? What is she thinking.” The whole thing finally got back to Gaga, who had no clue. She’d never heard the parody ? she didn’t even know I wanted to do it. Her management was trying to protect her. When she finally heard it, she said OK.

Is permission necessary?

You don’t need permission, but I get it because I want to take the high road. I want a good relationship with the artists and everybody to be in on the joke.

Who’s been a happy target?

Michael Jackson and I weren’t pals ? we never went bowling together ? but he was supportive. I credit him for giving me a big leg-up. “Eat It” [the parody of “Beat It”] brought me international fame. The very fact he said yes gave me credibility. I was able to convince other artists to say yes by telling them “Michael Jackson didn’t have a problem with a parody.”

Did Madonna really call you to suggest a parody?

It wasn’t quite as direct as that. Madonna was talking with a pal of hers. “Like a Virgin” was everywhere on the radio and she said “I wonder when Weird Al is going to do ‘Like a Surgeon.’ ” Madonna’s friend knew my manager, who got back to me with it. I was like “Good idea, Madonna. Thanks!”

You’ve been recording parodies since you were a kid. Back then, radio was your outlet, then MTV. Now you’ve adapted to YouTube.

It’s a huge promotional tool and MTV hasn’t played music videos for the last couple of decades. My parody “White & Nerdy” [a spoof of Chamillionaire’s “Ridin’”] has gotten over 100 million hits at various portals on the Internet.

Is there anything that’s taboo?

My humor is clean, but not squeaky clean. But I don’t swear in everyday life, so I’m not going to in music. I try to figure out how much bad taste is too much bad taste.

Speaking of taste, there are a lot of food references in your work, but not much sexual innuendo. Is food funnier than sex?

That’s a very broad question. I’d say it depends on the food and on the sex. If it’s baloney versus missionary position, baloney is much funnier.