Rihanna and Chris Brown have become embroiled in a bitter Twitter exchange.

The on/off couple called it quits last week, and seemed to engaged in a jealous exchange on the social networking site with tweets sent to their followers.

On Friday (10.05.13) Chris, 24, hinted the singer had been unfaithful following reports she recently partied with her ex JR Smith on Tuesday (07.05.13).

He wrote: '''She's not mine if she's everybody elses.''

His tweet came a day after Rihanna seemed to take a cryptic shot at the rapper - who is probation for assaulting the 'Stay' hitmaker in 2009 - when she posted an Instagram photo.

The image featured the words: ''If I drop all of my hoes for you and we still don't work out you owe me some hoes.''

Chris had previously spoken kindly about Rihanna and the end of their relationship, claiming he would ''always'' have feelings for her.

He said: ''I'm always going to love that person ... [but] I can't be focused on wife-ing someone that young -- I need to step forward and be a man and be the best Chris Brown I can be.''

On Wednesday (08.05.13), Rihanna seemed to respond to his comments, adding ''settling [wasn't] an option'',

Writing on Twitter, she added: ''Settling is not an option! Nothing less than 100% loyalty, honesty, and respect!! Love ain't for kidz #butimsleeptho (sic)''