Chris Brown & Rihanna

She's single ... and it appears Chris Brown's ex-GF is ready to mingle -- 'cause Karrueche Tran hit up the L.A. club scene this weekend on a serious girls' night out.

Tran and two of her girlfriends rolled up to Greystone Manor in Hollywood in a tricked out blue Porsche Panamera shortly after midnight Monday morning.

As we previously reported, Tran was pissed when she saw Brown's bizarre breakup video statement ... in which he questioned if it's possible to love two people at once.

Adrienne Maloof has no problem overlooking Chris Brown's violent history -- telling TMZ she LOVES him -- even as she's accusing her estranged husband of abusing their children.

Maloof -- who is knee deep in a nasty divorce with Dr. Paul Nassif -- was outside B.O.A. Steakhouse Friday night ... when we asked the question on everyone's mind ... what she thinks of Rihanna and Chris Brown reuniting?

Maloof skirted the question at first, but finally says ... "I love Chris Brown, he's very talented. My children love his music. He's awesome."

Interesting comment ... considering Adrienne is getting ready to square off with Paul in a child custody dispute filled with allegations of violence against their 3 boys.

As TMZ reported, Adrienne was recently awarded temporary custody of the kids when she accused Paul of physically abusing them -- a claim Paul adamantly denies.

Chris Brown's recently axed ex-girlfriend has 3 words for him -- shut your mouth ... because she is PISSED C.B. made that highly-produced drunken video confession about loving two chicks.

Sources close to Karrueche Tran tell TMZ ... she's livid over the fact that Brown blasted their personal problems all over the internet with his ridiculous video -- in which he confesses to loving Rihanna and Karrueche at the same time.

If Chris thought the video would soften the blow of breaking up with Karrueche ... he was dead wrong. We're told KT feels Brown should have kept his feelings private and she's disappointed and hurt by his decision to broadcast their personal life.

As TMZ previously reported ... Brown announced his split from Karrueche earlier this week by stating, "I love Karrueche very much but I don't want to see her hurt over my friendship with Rihanna."

He later posted this video, claiming he has feelings for both ...

Chris Brown dumped his girlfriend Karrueche for Rihanna, then immediately said he's still in love with both of them. Can Chris have his Rihanna and eat it too? We gotta ask ...

Chris Brown just released a hyper-produced propaganda break-up video ... in which he drunkenly says he loves BOTH Rihanna and his ex-GF Karrueche Tran ... and says, "I'm not trying to be a player ... I just care too much sometimes."

It seems to be an artsy-fartsy way to explain his decision to kick Karrueche to the curb after being seen with Rihanna this week.

In the footage, Brown tries to hammer home the point that he's wasted -- intercutting footage of himself poppin' champagne, partying in a nightclub and looking slouched over while smoking. At one point he says, "I'm a little drunk, so I'mma be honest ..."

It's unclear when the footage was shot ... but two hours before Brown posted the video, Rihanna tweeted, "Ain't nobody bidness..... But mine and my baby!"

He never mentions either woman by name in the video, but there are shots of both RiRi and Karrueche spliced into the 1:27 clip.

Chris Brown and Rihanna got real -- like REAL real -- by getting cuddly at Jay-Z's concert! Then Chris got REAL by dumping his GF!! Too REAL, right?

Brown announced this morning that he kicked his GF Karrueche Tran to the curb because he wants to concentrate on his "friendship" with Rihanna ... and by "friendship" he means he's going to take her to Bone Town.

Chris Brown's ex-girlfriend ain't buyin' that Chris is "just friends" with Rihanna ... telling her peeps she's convinced they were bangin' behind her back.

We spoke to multiple sources connected to Karrueche Tran ... who tell us KT feels betrayed by Chris because he had promised her that she was the only woman in his life ... especially when she probed him about his feelings toward Rihanna.

We're told Karrueche had suspected something was up between the two of them for weeks because Chris was acting differently -- going to clubs alone, acting distant and ramping up his public appearances with Rihanna.

Sources say Karrueche told friends she truly loved Chris ... and felt that the relationship was great until Rihanna let Brown back into her life.

Chris Brown says he has officially BROKEN UP with his girlfriend Karrueche Tran ... explaining, "I don't want to see her hurt over my friendship with Rihanna."

Brown just made the announcement ... saying, "I have decided to be single to focus on my career. I love Karrueche very much but I don't want to see her hurt over my friendship with Rihanna."

He adds, "I'd rather be single allowing us to both be happy in our lives."

The announcement comes after Brown and Rihanna were spotted together at the Jay Z concert in Brooklyn last night. The two had been hanging around each other A LOT lately ... and did some hardcore flirting at the MTV VMAs.

Karrueche had posted a cryptic tweet last night reading, "Bye baby."

Rihanna and Chris Brown aren't even trying to hide it anymore -- 'cause it looks like they were getting cozy at the Jay-Z concert tonight ... and, based on Twitter, everyone in Brooklyn saw it.

A pic taken from behind RiRi and Chris at Barclays Center is burning up the Internet -- they're seated in VIP ... he's on the left, she's on the right.

No physical contact -- in the photo, anyway -- but Chris' right arm is stretched around the back of Rihanna's chair.

This reunion comes the night after Chris and Rihanna were spotted at the same table in an NYC nightclub.

They were also seen leaving the same hotel on Wednesday -- and, for what it's worth, Chris' blind-as-a-bat GF Karrueche tweeted "Bye baby" ... just a couple hours before tonight's concert.

Apparently, Jay-Z is so powerful he can turn back time ... to 2008.

Chris Brown and Rihanna are barely trying to hide it anymore -- getting up close and personal at a NYC nightclub late Monday night ... then carousing at Rihanna's hotel for hours.

Chris and Rihanna hit up Griffin nightclub in the Meatpacking District -- we're told they arrived 5 minutes apart, and quickly ended up at the same table. Sources inside the club say the two were all over each other, and even disappeared together in a bathroom for 20 minutes.

People inside the club say the duo were kissing and hugging out in the open.

The two left the club separately -- but hours later, Chris was spotted leaving the Gansevoort Hotel, where Rihanna was staying.

By the way, Tuesday afternoon, Chris' clueless GF Karrueche tweeted that Chris sent her roses, a teddy bear and chocolates -- maybe a lame, "I'm sorry."

So we gotta ask ...

Chris Brown tested positive for marijuana recently in Virginia, where smoking weed is illegal, but the judge said she would NOT revoke his probation.

Chris was just in court for a probation progress report hearing in his felony battery of Rihanna -- and according to probation report docs ... Brown failed a drug test on June 18 in Virginia, where he was fulfilling his court ordered community service.

According to the probation report, Chris told his probation officer he had smoked weed in California -- where he has a medical marijuana prescription -- and then failed the test in Virginia, where weed is illegal ... prescription or no prescription.

Judge Patricia Schnegg said she never ordered Brown to undergo mandatory drug testing as part of his probation, so she cut him a break ... this time ... letting him off with a stern reminder to obey all laws.

Schnegg also ordered Brown's entire case moved back to California because that's where he lives now.

Chris Brown's new neck tattoo is NOT Rihanna's face ... or a battered woman for that matter -- at least according to the singer's rep -- who insists it's actually a Mexican-themed skull in commemoration of Dia de los Muertos.

Chris' rep tells us, "His tattoo is a sugar skull (associated with the Mexican celebration of the Day of the Dead) and a MAC cosmetics design he saw. It is not Rihanna or an abused woman as erroneously reported."

According to the tattoo artist, CB brought him the "sugar skull" design from a MAC ad the singer had seen.

Chris Brown insists his brand new neck tattoo is NOT a bizarre homage to Rihanna -- but if you look closely, the resemblance is uncanny.

The last photo we've seen of Chris without the tat is dated August 30th and the above photo was taken on September 1st, so CB got the ink job at some point between those two dates ... nearly a week before Rihanna kissed him at the MTV VMAs.

Sources really close to Chris tell us any similarities the tat has with Rihanna's face are purely coincidental -- "It's a random woman."

But we still gotta ask ...

Rihanna showed her true colors at the VMAs this week, taunting Chris Brown's girlfriend by kissing him and love-tapping him on the head for all to see. So we gotta ask ...

The biggest moment at the MTV VMAs wasn't aired on TV ... it was captured on a live Internet feed ... when Rihanna approached Chris Brown on her way to her seat and gave him a HUG AND A KISS.

It all happened live on MTV's "VIP Seating Cam" -- Rihanna made a beeline for Brown before the show ... and when she got close, Brown stood up and then Rihanna kissed him on the cheek.

The two then hugged each other ... and when it was over, Rihanna walked back to her seat.

It's the first time we've seen the two actually touching each other since the infamous beating incident back in 2009 ... the night before the Grammys.

Recently, Rihanna has been opening up about her feelings for Brown ... telling Oprah she still cares about him ... calling him "the love of my life."