Chris Brown set tongues wagging when he was  joined by his ex Karrueche Tran at his birthday party on Friday, with his  girlfriend Rihanna nowhere in sight.

The singer celebrated his 24th birthday –  which isn’t actually until May 5th – at the Emerson nightclub in Los  Angeles.

Rumours have been circulating that there may  be trouble in paradise once again for the on/off couple, which was only made  worse by Karrueche’s attendance.

Birthday babes: Chris Brown celebrates his 24th birthday  at Emerson Theatre in Los Angeles, California on Friday with a handful of  scantily-clad womenHowever source told HollywoodLife.com that  Chris and Karrueche are ‘cool friends’ and Rihanna is OK with them  hanging out  from time to time.The insider added that he and the 25-year-old  Stay singer are ‘into each  other way too f***ing much’ to let his friendship  with Karrueche come  between them.

Chris,  who is still on probation for  violently beating Rihanna in 2009,  previously revealed he would always have a  soft spot for his former  flame – who was recently said to have moved on with  NBA star John Wall – because she supported him during the worst time in his  life.

Yum! The musician indulged in savory cupcakes at his  bash

 

He said: ‘She was my friend through  it all.  It was a friendship more than a relationship. I still love her,  but at the end  of the day, it’s like I got love for her. She gone always be my  homie!’

He also said he wishes ‘all the best to her.  We still have a clothing line. I only  want her to progress. I don’t want to  stop her blessings.’

Chris is set to host a huge birthday bash in  1 Oak nightclub in Las Vegas on  Saturday and is trying to convince Rihanna to  join him for the night  after she was forced to postpone her concert in  Brooklyn, New York on  Sunday because the Brooklyn Nets need the venue to  compete in the  playoffs.

Star-studded event: A host of famous faces joined for  the birthday bash

A source said: ‘That’s his number one and he  wishes she could be with him on his birthday just like he was with  her.

‘But that’s just how it goes sometime. They  can’t be together every second.’

Stay singer Rihanna is currently in New York  for her Diamonds World Tour, and sources have revealed that work commitments are  preventing the couple from finding much time to spend together.

A source told HollywoodLife: ‘It’s up and  down sometimes, the s**t is even sideways. Everytime some s**t pops off between  them, they blast that s**t all over social media, and they  shouldn’t.

‘But when they’re far apart, that’s how they  act out towards each other when one of them doesn’t get their own way. It’s  crazy as f**k, but it’s how they get down.’

Does Rihanna know? Former flame Karreuche Tran helped  Brown celebrate in some eye catching boots

Newly single: Topshop heiress Chloe Green wore a  see-through top and leather trousers as she joined Brown on Friday  night

Possibly trying to take his mind off his  far-away girlfriend, Chris hit the town to celebrate his upcoming birthday with  some famous friends and tasty treats.

The heavily tattooed singer was joined by  Christina Milian, David Hasslehoff, Chloe Green and ex-girlfriend Karrueche Tran  as he partied the night away at indulged in delicious cupcakes.

He kept it casual for the celebration,  wearing khaki-coloured chinos and a white T-shirt. He wore an open chequered  shirt and completed his look with a pair of black hi-top trainers.

Many happy returns: Chris partied the night away… but  Rihanna was nowhere to be seen!

Tran – who was dumped by Brown when he got  back with Rihanna last year – showed off her slimline figure as she helped her  ex celebrate.

Opting for a LBD, the model accentuated her  trim pins by pairing it with a pair of white fringed boots.

Edging the ensemble up, she teamed it with an  oversized denim jacket and a bright red clutch bag.

Topshop heiress Chloe Green also attended in  a white see-through top and leather trousers.

One wish: A sources said that Chirs ‘wishes she  [Rihanna] could be with him on his birthday just like he was with her’

Duo celebration: DWTS’ Cheryl Burke was also celebrating  her birthday at Emerson on Friday

Cheryl Burke also celebrated her birthday at  Emerson on Friday night, spotted holding up her glamourous birthday  cake.

Though her presence was ironic considering  her history with Brown.

After Chris Brown performed on Dancing With  The Stars in 2011, the pro dancer told Extra: ‘As  a victim of domestic violence, I don’t agree with him coming on the show, but  it’s out of my control.’

Sports fan: Rihanna looked glamorous as she attended the  Chicago Bulls vs the Brooklyn Nets game on Saturday

Those aren’t basketball shoes: The singer’s  gladiator-style heels sure attracted attention

Kind gesture: Rihanna signed an autograph for one  thrilled young fan

Meanwhile, Chris’ ex-girlfriend Rihanna  enjoyed her own celebration – at a basketball game.

Rihanna looked glamorous in a slinky black  outfit and sexy black lace-up heels as she sat courtside to watch the Chicago  Bulls play against the Brooklyn Nets on Saturday night.

Rihanna’s ran her fingers through her long  tresses as she watched the action. At one point, the singer even paused to sign  an autograph for a young fan.

Hoops fan: Rihanna on Saturday watched the deciding  seventh game in the first-round NBA basketball playoff series between the  Brooklyn Nets and the Chicago Bulls in New York City

Read more: DailyMail