It seems Rihanna has finally had enough of Chris Brown ... the singer has "unfollowed" her ex-boyfriend on Twitter after he released a new diss track that appears to be aimed at her.

The song in question is a remix of Kanye's TheraFlu -- in which Brown freestyles the verse, "Don't f*ck with my old bitches ... like a bad fur ... every industry n*gga done had her."

He continues, "Trick or treat like a pumpkin ... just to smash her."

Hours after Brown released the track last night, Rihanna stopped following Brown on Twitter -- a HUGE move -- and one that's leading many to assume Rihanna believes the verse is about her.

A short time later, Brown unfollowed Rihanna.

We reached out to Rihanna's rep -- so far, no comment.

Screw the brutal, face-smashing beating in 2009 ... Chris Brown is the HOTTEST R&B artist out right now -- which is why Rihanna says she reached out to CB to collaborate on two new songs.

Rihanna called Ryan Seacrest this morning on KIIS FM, explaining her choice to record two duets with the man who brutalized her three years ago -- "I reached out to him about doing ‘Birthday Cake’ because that’s the only person that really -- it made sense to do the record. Just as a musician -- despite everything else -- that was going to be the person."

She said, "I thought about rappers, and I’ve done that so many times, and the hottest R&B artist out right now is Chris Brown. So I wanted him on the track."

It's not personal ... it's business ... right? 

Chris Brown’s GF is scared to leave her house without bodyguards by her side -- and she's telling friends, it's all because Rihanna's crazy fans are threatening to kill her.

In case you missed it -- there was a lot of speculation last week that Rihanna dissed Karrueche Tran on Twitter -- posting a pic of a bag of rice cakes wearing sunglasses ... with the caption, "Ima a make u my bitch."

The joke -- Karrueche's Vietnamese ... rice cakes ... etc.

But several of Rihanna's fans took the joke one step too far -- unleashing an avalanche of violent threats on Karrueche ... like "I hope Rihanna beat the dog shit outa yo ass!" ... "Watch yo back" ... and "I will kill you."

Rihanna never admitted the rice cake jab was directed at Karrueche -- but sources close to Karrueche tell TMZ, she now refuses to leave her house without Chris Brown's hired muscle by her side.

As for Karrueche's infamous BF -- we're told CB is 100% supportive of his new lady ... despite getting close with Rihanna recently ... and is urging her not to worry.
 
The real lesson here -- don’t date Chris Brown.

Chris Brown didn't shy away when the DJ blasted a Rihanna song at an Orlando nightclub this weekend -- instead, he proudly sang along with EVERY lyric ... and TMZ has the footage.

It all went down at Club Vain on Sunday night during an NBA All--Star weekend finale party.

Chris was hanging on the main stage ... with everybody looking at him ... when Rihanna's "We Found Love" began to pump through the speakers ... and Chris made sure everyone knew he's a HUGE fan of the song.

It's the latest in what seems like a public reconciliation between the two sides -- earlier this month, the two collaborated on remixes of each other's songs.

Chris Brown is being watched ... watched closely by the D.A. who prosecuted him for beating Rihanna ... because the latest incident in Miami could trigger a full court press in L.A. to send Brown to prison.

Sources tell us ... the L.A. District Attorney's Office is well aware of the robbery-by-snatching investigation of Brown in Florida ... and they're waiting for the L.A. County Probation Dept. to recommend what action, if any, should be taken.

In case you forgot ... and how could you forget? ... Brown was sentenced to 5 years probation for beating Rihanna in 2009 ... and one of the terms is that he obey all laws.

If officials determine the allegations against Brown are true -- that he "snatched" a cell phone from a woman in Florida -- his probation could be revoked and he could be thrown in prison for 4 years.

As TMZ first reported, an arrest warrant has not been issued in Florida ... at least not yet.

Chris Brown and Rihanna are dangerously close to getting back together, sources close to the ex-couple tell TMZ -- but the singers' friends are desperately trying to keep them apart ... for their own good.

According to sources, Rihanna is still head over heels for Chris -- despite that fateful night 3 years ago when he brutalized her -- and if it weren't for the media and her fans, she would already have taken him back.

We're told Chris also has extremely strong feelings for Rihanna -- current girlfriend be damned.

Now, sources tell us, Rihanna and Chris' friends are terrified they'll get back together -- and they're doing everything they can to prevent a possible reunion.

According to sources, friends on BOTH sides have expressed extremely strong reservations to Ri and CB about spending so much time together ... warning it's a terrible idea ... personally AND professionally.

But with Rihanna's birthday ... Chris and Rihanna's duets released this week ... friends fear they're fighting an uphill battle.

As one source put it, "You can't hold back love."

WWE heavyweight champion CM Punk is lashing back at Chris Brown ... claiming the singer isn't just a liar ... but a total "coward" who never truly "paid" for what he did to Rihanna.

Punk released a video statement moments ago ... in response to Brown's allegations that he's a steroid-abuser with an inadequate penis.

In his video, Punk starts out by saying he's "a proud life long drug free straight edge individual" ... and then spends the next minute BLASTING Brown.

"Chris and I come from different worlds. I don't have an assistant. I don't have a body guard.  I don't have a manager or a PR person telling me to delete tweets like Chris does, and I don't hit women. Period."

He adds, "[Chris] has made the wrong accusations to the wrong person because I can defend myself."

Punk then challenges Brown to a no-holds barred fight for charity ... and says, "I will choke you out and I will make you feel as weak and as powerless and scared and alone as any woman who has the misfortune of knowing a sad cowardly little boy such as yourself."

Your move, Chris.


5:16 PM PT -- Chris Brown responded:

I really hope this 15 minutes of fame is paying you for the long run becuz music last forever! Wrestlers come and go according to ratings!

— Chris Brown(@chrisbrown) February 22, 2012

Rihanna collaborating with Chris Brown has the newsroom up in arms -- because everyone still remembers what he did to RiRi's face. Are we crazy? (That was rhetorical)

Rihanna and Chris Brown have reconciled ... at least professionally ... because the former couple have collaborated on 2 brand new songs.

It's only been 3 years since Brown pummeled Rihanna's face during a late night argument in L.A. ... but the singer and her ex-con ex-BF have each released songs featuring the other's voice. One is a remix of Rihanna's song, "Birthday Cake" and the other is a new version of Chris Brown's, "Turn Up the Music (below)."



Both songs hit the Internet this week ... and both Rihanna and Brown have been pushing the songs on Twitter.

The songs seem to prove the rumors ... that Rihanna has forgiven Brown and is willing to move on. Earlier this week, Brown tweeted Rihanna "Happy Birthday" ... and Rihanna actually responded, "Thanks."

Rihanna is currently in London (see photo above) ... and Chris Brown was most recently seen in Miami.

As we previously reported, Brown is currently in a relationship with a woman named Karrueche Tran ... and we're told the two seem very happy together.

Lost in all the Chris Brown/Rihanna possible reunion madness is the fact that CB has a serious girlfriend -- and sources close to her tell TMZ the two of them are doing quite well in their relationship ... thank you very much! 

Sources close to Karrueche Tran tell TMZ she is unfazed by the recent rash of RiRi rumors. In fact, we're told CB and KT are now actually living together. 

As for CB showing up to Rihanna's birthday party, we're told that didn't bother Karrueche either ... because he came home to her that night and whisked her to Miami the next day to celebrate Valentine's Day.

According to our sources, Chris professes his love to Karrueche daily and he has no plans to leave her for Rihanna.

Almost makes you say, "Awwww" ... until you remember ...

Chris Brown was so paranoid about keeping his attendance at Rihanna's birthday party a big fat secret -- he actually tried to FORCE partygoers to sign confidentiality agreements ... TMZ has learned.

Sources tell us, Chris refused to enter the private party Monday night at the famous Hearst Mansion in Beverly Hills until everyone signed an NDA -- sending his henchmen in beforehand to gather every partygoer's signature.

We're told although they didn't get EVERYONE to sign -- Chris eventually walked in ... and spent a huge chunk of the night nuzzling up against Rihanna.

According to sources, the two got real intimate -- sitting next to each other, talking, and holding hands ... all perfectly legal ever since the restraining order was lifted.

As for the rest of the party -- we're told it was jam-packed with celebs including Katy Perry, Bruno Mars, and Chris Martin (no Gwyneth).

Rihanna's cake was pretty badass too -- a giant spliff ... with a small Rihanna made out of icing, riding it like a horse.


Eat your heart out, Miley.


Chris' rep tells TMZ, confidentiality agreements were distributed only to workers at the party and anyone who was caught videotaping/snapping a pic of CB.

Asking people to sign confidentiality agreements AFTER they've already taken pics -- priceless.