Brown was widely believed to be the mystery collaborator, with reports suggesting that he recorded both a singing and a rap verse for the interlude track lifted from Ri's latest album, Talk That Talk.
Rihanna also appeared to address the collab rumours on Twitter.
"They can say whatever, Ima (sic) do whatever... No pain is forever, YUP! YOU KNOW THIS," she wrote on Friday.
"Let them be mad!!!!" Brown also tweeted. "We make music. Don't like it, don't listen! Turn up the music remix is coming soon too! Guess who's on it?"
And just in time for Rihanna's 24th birthday, Brown yesterday tweeted a link to the new, extended and blush-worthy version of the songbird's Birthday Cake.
"@rihanna goo.gl/ttRJR YIKES!!! Cake, cake, cake!," Brown tweeted, while linking to a free (and subsequently removed) download of the track.
Moments later, Rihanna replied and tweeted out a remixed version of Brown's Turn Up The Music, featuring her guest vocals.
"#RihannaNavy Come and put ya name on it!!!!! RT @chrisbrown: @rihanna goo.gl/ttRJR YIKES!!! Cake, cake, cake!" she wrote, along with a link to the track, which Brown performed at the Grammys just last week
"@chrisbrown Turn up the music remix #RihannaNavy #Teambreezy enjoy!!! vimeo.com/mechanicaldumm... "
Check out the Turn Up The Music remix below:
"Its a download OVERLOAD!!!!," Rihanna later tweeted. "Working on more links for u guys, so errbody could have some #CAKE,"
Go hunt for the Birthday Cake remix, featuring Brown spouting some seriously NSFW lyrics, yourselves.
Birthday wishes
The former couple also raised eyebrows with another exchange on Twitter on Monday.
Brown wrote, "HAPPY BIRTHDAY ROBYN!" to the singer, aka Robyn Rihanna Fenton.
Rihanna responded with a "Thanks!" and re-tweeted his message.
Brown pleaded guilty to assaulting Rihanna on the eve of their appearances at the Grammys in 2009. He was sentenced to five years of probation for the incident.
A Los Angeles judge last year eased the terms of a five-year restraining order against Brown, after Rihanna indicated she had no objection.
"It doesn't mean we're gonna make up, or even talk again," she told Rolling Stone at the time. "It just means I didn't want to object to the judge. We don't have to talk again ever in my life. I just didn't want to make it more difficult for him professionally.
"What he did to me was a personal thing. It had nothing to do with his career. Saying he has to be a hundred feet away from me, he can't perform at awards shows, that definitely made it difficult for him. That was the only thing it was going to change, so I didn't care."
Meanwhile, one of Brown's most vocal critics, country music star Miranda Lambert, continues to fuel her feud with the Kiss Kiss singer.
Lambert took to Twitter last week to express her disappointment to see Brown honoured and performing at the Grammy Awards.
She fumed: "Chris Brown twice? I don't get it. He beat on a girl...Not cool that we act like that didn't happen."
Brown later lashed out at his critics in a series of tweets, which were subsequently deleted.
He wrote: "Strange how we pick and choose who to hate! Let me ask u this. Our society is full of rappers (which I listen to) who have sold drugs (poisoning).
"But yet we glorify them and imitate everything they do.
"Then right before the worlds eyes a man shows how he can make a Big mistake and learn from it, but still has to deal with day to day hatred! You guys love to hate!!! But guess what???
"HATE ALL U WANT BECUZ I GOT A GRAMMY Now! That's the ultimate F*** OFF!
Lambert brought up the singer again during her concert at the University of Massachusetts on Thursday.
Holding up a handwritten poster that read, "Take notes Chris Brown", she told the audience, "I just have to speak my mind, because where I come from, beating up on a woman is never okay. So that's why my daddy taught me early on in life how to use a shotgun."
She then dedicated her song Gunpower and Lead, about a woman preparing to kill her abusive husband when he gets out of jail, to Brown.
Brown later fired back: "Using my name to get publicity? I love it! Perform your heart out," he wrote.
"Go buy @miranda_lambert album! So motivational and "PERFECT"!
"Goodnight to all the people who live life and aren't stuck I the past! TEAM BREEZY is my family! Positivity and blessings!"
Lambert's counter-attack? I'd put money on this dive-bombing seagull being on her payroll.
* What do you think of Rihanna and Brown collaborating? Sound off in the comments below.
- Blogger Bites Back
