LMFAO on Famous Family, Zebras, Keeping the Party Rockin'

July 12, 2012— -- If Elvis was the king of rock 'n' roll, the guys of LMFAO are the kings of party rockin'.

Their psyched-up electropop songs have become radio, and, well, party, staples. Their "Party Rock Anthem," in which they encourage you to "shake that," earned them over 460 million views on YouTube, putting it in the top 10 all-time most watched videos. And fans young and old now shamelessly boast that they are "sexy and [they] know it," thanks to another LMFAO hit.

Watch the full story on "Nightline" tonight at 11:35 p.m. ET

LMFAO's vibe is laid-back party animal, but don't be fooled. The duo is shrewdly turning partying into profits. Their songs have been used in several TV commercials, including "Everyday I'm Shuffling" for Kia and "I'm Sexy and I Know It" for M&Ms.

In fact, Adele's "Rolling in the Deep" was the only song to out-sell their "Park Rock Anthem" on iTunes last year. Her powerful vocals pitted against their electro-pop, but LMFAO scoffs at critics who say they aren't real singers.

"Everything you've heard, OK, I've mixed and mastered," Redfoo said. "It's on the laptop, we record everything at the house, we record our own vocals. I think we're the only artist that masters their own stuff."

Numerous music video parodies of LMFAO's popular tracks have cropped up online and received their own fame. Three farm guys from Kansas have become Internet sensations with their LMFAO parody, "I'm Farming and I Grow It," which has over 5.4 million views.

So just who are these two guys who are taking "shots, shots, shots, shots, shots, shots" with everybody?

Redfoo and Sky Blu are Motown royalty as the son and grandson of legendary impresario Berry Gordy, Jr., who launched the careers of the Jackson 5 and Diana Ross. Redfoo is Sky Blu's uncle.

"I realized my family was famous because I was looking in my history book and I saw my grandfather," Sky Blu said.

"It was weird," Redfoo said. "People thought it was a skill that we were, you know, Berry Gordy's offspring, like it was a talent."

But it was Sky Blu's not so famous grandmother who suggested the name "LMFAO," which is text language for "Laughing My F---ing A-- Off."

"I said, 'hey grandma, what do you think of our new name, 'Sexy Dudes,' and she replied 'LMFAO, you can't be serious,'" Sky Blu said.

The guys have also gotten noticed for their bright neon street fashion. Redfoo almost always works zebra stripes into his look and said his love for zebra stems from his childhood.

"I'm half black, half white, domino, like Sky Blu, we're both mixed," Redfoo said. "A lot of kids would call me 'zebra,' 'look, a zebra!' You know, zebra stripes are black and white, and that was my first obsession with zebras because I was compared to one."

As former comics, LMFAO's techni-color performances seemed designed to make people laugh, and that's the point, for the audience to sing and dance along with them. But videos of kids still in diapers gyrating to their moves and singing their racy lyrics have zipped across the Internet. LMFAO said their act was not for all audiences.

"We definitely imagined a demographic that would be listening and it wasn't 4-year-olds," Redfoo said. "Basically adults."

"A lot of girls," Sky Blu chimed in.

But the guys claim that they have had mothers praise them for their music, and said one parent even told them that their child's first word was "wiggle," a lyric from their song, "I'm Sexy and I Know It."

"Seriously they love the fact that their kids are so happy," Redfoo said. "They dance around, they shuffle around and the parents are thanking us because they get to enjoy now music because the parents love the music, the kids love it. They come to concerts."

But while LMFAO's music promotes feel-good partying, some critics wonder if their lyrics are glorifying binge drinking -- remember "shots, shots, shots, shots, shots, shots"? -- and sending the wrong message to impressionable young fans. LMFAO denied that was ever their intension.

"It's not binge drinking, it's celebratory drinking," Sky Blu said. "It's getting to the point."

"Yeah, you grab your friend, let's go take a shot," Redfoo said.