Karrueche Tran dumped Chris Brown over his "inappropriate" text conversations with other women.
The 25-year-old model reportedly ended her romance with the 'Yeah 3x' hitmaker in February after visiting him in rehab - where he was on a court-ordered anger management programme - and finding his phone was filled with messages from girls, gossip website TMZ reports.
Karrueche is said to have been particularly upset because she had been "nothing but supportive" to her on/off lover throughout his recent problems, and she also had no idea he had allegedly been getting close to women in the Malibu clinic until long after they split.
Earlier this month, the 'Fire China' singer was kicked out of rehab after breaking three "internal rules", one of which was specifically imposed on him, which was to stay at least two feet away from any women.
The rule was made because he is still on probation for his 2009 assault of then-girlfriend, Rihanna, but he broke it by "touching elbows and hands" with a woman.
And he was also said to have been involved in "some sort of sexual encounter with a woman at the facility" earlier this month, but it was not cited as evidence to thrown him out.
The 24-year-old star is now being held in a Los Angeles jail until a probation violation hearing on April 23.
Being thrown out of the court-ordered anger management programme - which was extended from an initial three-month period, which Chris had completed, in light of his facing further legal problems - was considered to be a violation of his probation.
Chris' legal troubles in Los Angeles stem from the assault of his then-girlfriend Rihanna in 2009.
In a separate case, the 'Turn Up the Music' singer also faces a charge of misdemeanour assault in Washington D.C., which will be heard on April 17.

January Jones wants to sleep with Rihanna.
The 'Mad Men' actress - who has never revealed the identity of the father of her two-year-old son Xander - has a crush on the 'Diamonds' singer, and also legendary late actor Paul Newman, who died in 2008 aged 82.
Asked by online magazine Violet Grey who she would "most want to go to bed with, dead or alive", she replied: "Paul Newman or Rihanna."
January - who posed nude for a series of raunchy photographs for the publication - admitted she likes to be "mysterious" but also wants to "shock" people and allow them to form opinions of her based on her actions.
She said: "I prefer to remain mysterious and have people make their own judgment calls about me than to always have to explain who I am and what I'm about.
"I try to take risks and shock people a little bit, it's important to provoke some sort of emotion, negative or positive."
And the 36-year-old beauty spoke of her awe of her friend and 'Mad Men' co-star Jon Hamm.
She said: "I think he's amazing. Very kind and generous, well read, very strong but easily vulnerable, very funny but also dark. My friend."

Alec Baldwin has bought a new home in the Hamptons.
The '30 Rock' actor recently confessed he wants to leave New York because he wants a more peaceful life but despite claiming he's beginning to "crave" Los Angeles after more than 30 years in the Big Apple, he's now purchased a new property in East Hampton and plans to spend a lot of time there, according to the New York Post newspaper.
News of Alec's house purchase comes after he announced during a talk at the at the Guild Hall Academy of the Arts Lifetime Achievement Awards on March 10 that he wanted to sell his home in the area, further adding to the belief he was planning to leave New York for good with wife Hilaria and their six-month-old daughter Carmen, but it now seems he decided to sell up to buy the new home.
In a recent essay, the 55-year-old star spoke of his reluctant desire to leave New York.
He said: "To be a New Yorker meant you gave everybody five feet. You gave everybody their privacy. And now we don't leave each other alone. Now we live in a digital arena, like some Roman Colosseum, with our thumbs up or thumbs down...
"I probably have to move out of New York. I just can't live in New York anymore. Everything I hated about LA I'm beginning to crave. LA is a place where you live behind a gate, you get in a car, your interaction with the public is minimal. I used to hate that. But New York has changed.
"I want my newest child to have as normal and decent a life as I can provide. New York doesn't seem the place for that anymore."

John Mayer "agreed" to buy counterfeit Rolex watches.
The 'Who You Love' singer is suing Robert Maron - a friend of Charlie Sheen - after he reportedly spent $5 million on what he believed to be authentic timepieces from the dealer, however lawyers for the salesman insist the crooner knew the watches contained "counterfeit" parts.
In a letter obtained by TMZ, Maron's lawyer, Eric George, claims Mayer expressed an interest in buying a fake Rolex Flat Dial on a message board in 2007.
He is quoted in the letter as saying: "Anyone who wants to sell me one of these watches can get these fake pieces off their hands and make a killing on it.
"I will even accept a letter from you as a dealer releasing you from any liability in having sold me a counterfeit dial. I will be buying these as counterfeits."
Initial reports claim John - who is a long-time collector of Rolex watches - was shocked to find one of the timepieces was a replica after sending it for repairs three years later.
He reportedly returned the watch and was given credit to buy another but now wants a refund for $656,000 he spent on seven other watches which Rolex have told him are counterfeit.
Meanwhile, 'Anger Management' star Charlie has also spoken out to defend his friend and slam the 'Gravity' singer for his "girlie" music.
He tweeted: "mr Mayer needs to park that milk toast
girlie drivel he calls muzak & leave the Patek/Rolex
prowess to the best watch expert alive (sic)"
He then shared a picture of his own watches, which he bought from Robert and described them as being in "perfect health and provenance".
Rolex is one of the world's most prestigious watch brands, with the coveted timepieces ranging anywhere from $5,000 with the most exclusive designs costing upwards of $500,000.

Emma Watson is being eyed up to star in 'The Little Mermaid'.
The 'Harry Potter' actress is being sought after by the director Sofia Coppola, who she has worked with in the past on 'The Bling Ring', to play the aquatic creature in the upcoming live-action movie.
A source told The Sun newspaper: "Sofia wants Emma, and the pair have such a respect for each other, it would be very surprising if they carry on without each other.
"Movie companies Universal and Working Title want to move quickly on this so expect an announcement soon."
Coppola had her sights on Hans Christian Andersen's tragic fairy tale as her next project after 2013's 'The Bling Ring', and will be bringing the classic children's story to life on the big screen.
However, fans shouldn't expect a repeat of Disney's bubblegum 1989 cartoon version about Ariel and talking crab Sebastian.
The director is thought to be planning a version in keeping with the original 1837 story, which sees the broken-hearted Little Mermaid commit suicide after the Prince marries another woman.
Coppola is taking over from 'Atonement' helmer Joe Wright - who was originally on board to direct but he is now currently working on 'Pan' - and intends to "move quickly" with the project.
The brunette beauty has young daughters Romy and Cosima with her husband, Phoenix frontman Thomas Mars, and is said to want to make a movie which her children can appreciate.

Brooke Vincent says the Webster family is incomplete without Helen Flanagan.
The 'Coronation Street' beauty, who plays Sophie Webster in the soap, feels the famous TV clan is missing a piece of the puzzle since Helen quit her role as Rosie Webster in 2012.
Brooke told BANG Showbiz: "With the Websters as a family unit, we kind of miss that bolshie, loudmouth sister."
While Brooke misses her on-screen sister, her TV dad Michael Le Vell will soon return to screens as Kevin Webster after being cleared of sex assault charges last year.
Sophie has recently fallen for the charms of 'Corrie' newcomer Maddie Heath and Brooke says it's been a pleasure to work with actress Amy Kelly.
She added: "Maddie is really big on the street, and it's really nice to have some chemistry again and a partner to work with. We've been working really hard recently so hopefully it'll pay off.
"The thing with Amy is she's fresh and new, and she's amazing. We do get on really, really well. It's really nice that they've picked such a good actress, as well as a really good friend."

James Lock doesn't trust his fellow male 'The Only Way Is Essex' cast mates.
The reality TV star insists Dan Osborne and Elliot Wright are the only males on the show who he would trust since everyone else is "out for themselves".
He explained: "I don't mean Dan when I say what I'm about to say, because he's a brother to me, there's no rivalry there. We've got lots of similarities, and I hold my hand up, he's doing a lot better than me at the minute.
"But I don't feel jealous - I'm happy for him. He's in my corner, and me, him and Elliot are on the same team.
"But most of the boys on the show, I wouldn't trust as far as I could throw them. Everyone's out for themselves, but that's just society, ain't it?"
James also shares a close friendship with Bobby Norris, who spends time joking with his co-star and girlfriend Danielle Armstong about techniques between the sheets while they film scenes for the show.
He added to Gay Times magazine: "I'm really good friends with Bobby Norris too. I feel really comfortable with gay men, and between scenes I'll always be having a laugh with Bobby. We have a lot of sexual banter and he's always talking to me about blow jobs and telling Danielle the best way to give me one."

The Rolling Stones will tour Australia and New Zealand in October.
The band were forced to postpone their seven-date tour Down Under, which was scheduled to kick off last night (19.03.14), after the frontman Sir Mick Jagger's long-term girlfriend L'Wren Scott, 47, committed suicide at her New York apartment earlier this week.
However, the promoters, Frontier Touring, reassured fans that the 'Brown Sugar' hitmakers would return in October to perform their '14 ON FIRE' tour, but the exact dates are yet to be confirmed.
The company told fans: "If the new dates are not suitable, rest assured you will be able to secure a refund.
"While we encourage fans to hold on to their tickets, the option to secure a refund is now available to you via the official ticketing agency you purchased from."
The group were "shocked" by the death of the fashion designer and are focusing on helping Sir Mick - who has been in a relationship with the former model for 13 years - get through this "awful time".
Drummer Charlie Watts said yesterday: "Needless to say we are all completely shocked but our first thought is to support Mick at this awful time.
"We intend to come back to Australia and New Zealand as soon as it proves possible."
Guitarist Ronnie Wood added: "This is such terrible news and right now the important thing is that we are all pulling together to offer Mick our support."

Paul Walker's mother wants guardianship of his daughter. Cheryl Walker has filed court documents seeking legal guardianship of Meadow, 15, following the death of the 'Fast and Furious' star in November because she believes the teenager's mum Rebecca S...

L'Wren Scott "struggled" to deal with being adopted as a baby.
An ex-lover of the fashion designer, Scott Tugel, 50 - who met L'Wren in the late 1980s and dated her for four months - claimed her issues stemmed from childhood because she hated that she was taken on by a Mormon family in Utah when she was a child.
He told The Sun newspaper: "She didn't want to talk about her previous life. She was creating a new identity for herself.
"She would get really down and solemn about being adopted. I think she struggled with that her entire life.
"Her adoptive parents did a great job and she loved them deeply. But I think that was the cause of her problems."
Meanwhile, her siblings Randall Bambrough and Jan Shane - who were also adopted by the devout couple - are hoping she will be laid to rest in her hometown where her family can mourn her peacefully.
Rob Shane, her brother-in-law, said previously: "Jan is hoping that Randy will do the right thing and bring L'Wren back to Utah. The family has a plot at a cemetery in North Ogden, and she would like her sister buried by their parents."
L'Wren - who was known as Luann Bambrough growing up - was particularly close to her brother, but hadn't spoken to her sister since the passing of their mother in 2008.
L'Wren, 47, who has dated Sir Mick Jagger for 13 years, was found hanged at her New York apartment on Monday (17.03.14) and the coroner confirmed yesterday (19.03.14) that her death was suicide.

'The Grand Budapest Hotel' cast had a "buzzing dinner party" every evening while filming.
The comedy which has an A-List cast including Ralph Fiennes, Jude Law, Tilda Swinton and Saoirse Ronan among others, was filmed in Germany and director Wes Anderson admits they bonded off set.
He told Hong Kong's Time Out magazine: "We took over this small hotel in the city of Görlitz in Germany. We had a cook I know from Italy who cooked for us and we had dinner together every night of the movie. Almost every night was a little buzzing dinner party."
The filmmaker was thrilled to team up with Fiennes, who plays concierge M. Gustave H, and although he admires his talent he admits the actor is "intense".
Anderson says: "He [Fiennes] was very funny in the film 'In Bruges', and the play 'God of Carnage'. I'd wanted to work with him for some time. I met him maybe ten years ago when I was at somebody's house and went into the kitchen and he was sitting there. I wanted to find something to do with him. He's intense. He's like a method actor, and I've not worked with anyone like that."

Taylor Momsen has hinted she would pose naked for Playboy.
The Pretty Reckless singer - who shows off her nude butt on the front cover of the band's new album 'Going To Hell', which is available now - insists she would be happy to listen to offers from Hugh Hefner's famous magazine but insists the shoot would have to have a "purpose" to it.
She told BANG Showbiz: "It's not something I'm pursuing. It would have to depend on a lot of factors [but] I don't rule anything out until it hits me in the face.
"It would depend on the shoot and if there was a purpose for it. I've done FHM and Maxim. FHM was based on the 'My Medicine' video and the Maxim shoot was a take on the rock and roll lifestyle of New York City. Everything has to have a story behind it, not just, 'Taylor getting naked again'."
The 20-year-old star appears naked in the video for her band's single 'Heaven Knows' and she made the decision to take off her clothes for the promo because she wanted to create a live action version of the LP cover, which she describes as a "beautiful, iconic and artistic photograph".
Speaking about the motivation for the album cover and the video, Taylor said: "I think people took the nudity to kind of an extreme, my point of nudity was to make it simple and striking, with the arrow, which is the symbol for 'Going To Hell'.
"The shot is so quick, it's not the point of the video ... you have to look past me to what is being played on the television [next to me]."
Taylor also isn't keen on being compared to Miley Cyrus, who appeared naked in the video for her single 'Wrecking Ball'.
She explained: "I think the comparison [between me and Miley] is so silly, because what we do is so different. I wasn't aiming to shock, I was aiming to create a beautiful image. I think every artist is different and whatever works for you works for you ... it's clearly working for her."