width=398The war of the words – or, we should say, song lyrics – between pop superstar Rihanna and Chris Brown's girlfriend Karrueche Tran is heating up!

Karrueche and Rihanna have been vying for Chris Brown's love for a few weeks now. Karrueche may be the official girlfriend, but rumors are flying that Rihanna and Chris may be getting back together – just today Star magazine claimed that they're even planning a secret wedding!

So far there have been no reports of physical confrontation, but they do seem to have gotten in quite the Twitter war. And, fittingly for a fight between a pop star and a pop star wannabe (or at least, wannabe girlfriend), it's been carried out almost entirely in song lyrics.

Rihanna fired the first musical salvo with her Birthday Cake Chris Brown collaboration, in which she said, taking a dig at Karrueche, who is of Vietnamese heritage: Sweeter than a rice cake, cake worth sipping, using a common slur – rice cake – for Vietnamese people. In case the target was not clear, she later tweeted a photo of a rice cake dressed in Karrueche's signature hoop earrings and sunglasses, leading many to question whether Rihanna had gone too far with the racism.

Karrueche Tran relatiated on her Facebook with the song lyric I win you loose!!! [sic] *nicki voice* – referring to Rihanna's main female rap nemesis, Nicki Minaj – I meannnn I got him, you got pictures of him. buwhaha..., with a friend posting another Minaj verse: I'm Angelina, you Jennifer / C'mon b-tch, you see where Brad at.

Well, despite all the gossip rags more or less agreeing that Rihanna's winning the battle for Chris Brown's heart, Rihanna didn't take Karrueche's Facebook jab seriously, firing back with the following lyric from Lil' Kim, Nicki Minaj's own female rap rival: I'm a leader, yall on some followin sh-t...comin in dis game on some modeling sh-t!

The modeling shit is likely a reference to the fact that Karrueche's only claim to fame aside from dating Chris Brown is that she's a model, whereas Rihanna worked her way up through the music biz, becoming famous in her own right even before hre drama with Brown (although that surely hasn't hurt).

Rihanna and Chris Brown seem to have taken their secret relationship to a new level, but Rihanna's jabs at Karrueche hint at some underlying insecurity. Only time will tell how this twisted, titillating lovers tangle turns out...