A$AP Rocky Says 'I'ma Have Fun' Performing With Rihanna At VMAs

'I'm just ready to do it already,' Rocky tells MTV News of his first-ever VMA performance.

LOS ANGELESA$AP Rocky has certainly come a long way. He watched last year's VMAs on television from his New Jersey home, but now the Harlem, New York, rap rookie is hitting the big stage, opening tonight's 2012 Video Music Awards at 8 p.m. ET/PT alongside Rihanna.

"I was at home watching Tyler win his award," Rocky told MTV News on Wednesday of the moment when Odd Future's Tyler, the Creator picked up his Moonman for Best New Artist in 2011. "Watching his mom be proud and sh--. That was a good day for hip-hop."

Rocky was just taking it all in Wednesday at the MTV radio forum, where various radio personalities get to chop it up with VMA talent.

"I'm just ready to do it already. I don't know what to expect — I've never been to an MTV [Video Music Awards] before," A$AP said. "I'm just gonna do what I do. I'ma do me, I'ma have fun. I'm excited."

On Tuesday, Rihanna released the remix of her new single "Cockiness (I Love It)" from her latest hit album, Talk That Talk, and she chose Rock to be the guest MC. The song can now be heard on Rih Rih's MTV artist page, and after her performance it will be available for purchase on iTunes. "It was already a hot song," Rocky said of the raunchy sex tune, which he and Rihanna will perform together during the big show. "She reached out to my people and made it happen."

"Pretty motherf---er with the Mossberg/ Jiggy motherf---er at my concert," Rocky spits to start the Bangladesh-produced track before he cranks up his verse with lyrics like, "Tell Rih Rih, I go re-re-tarded/ On the remix of the re-recording."

Check out behind-the-scenes photos of One Direction, Green Day and more at the 2012 VMAs!

A$AP is impressed by his bars on the record and told us that originally his verse was much longer than the version that fans now hear. "It really was longer, but I had to cut it down," he said. "I went in on that beat. I gave her like 32 bars. I went in."