Rihanna Karrueche Tran Instagram Battle Of Butts Over Chris Brown; Rihanna's Latest Butt Pic Hotter Than Tran? [Pics & Video]

A day after Karreuche Tran posted a photo of Rihanna-ex, Chris Brown, nuzzling her butt cheek on Instagram, Rihanna is serving up a steamy butt pic of her own from the set of her new music video for "Pour It Up."

The Karreuche Tran Instagram butt battle with Rihanna has been making Facebook look like geniuses for purchasing Instagram more than a year ago.

It all started after Chris Brown and Rihanna officially announced their breakup last week, but who knows how long it's really been going on.

Then, yesterday, Brown was spotted on the street after he rear-ended (pun, very much intended) someone while Karreuche Tran was in the car with him.

No word on whether Tran was in the "backseat" or not, but she did flash her backside on Instagram.

She posted a pic from back when her and Chris Brown were officially dating, showing Chris nuzzling her cocoa-butter backside.

The caption with the post was "TBT my birthday last year. Who's face am I gonna put my ass in this year? Lmao I'm kidding"

But that was just the beginning of the butt battle between two of the best looking ladies in the world: Rihanna and Karreuche Tran.

Not to be outdone by her former rival for Chris Brown's graces, Rihanna, on her BadGalRiri Instagram profile shared her incredibly perfect looking derrière.

The sexy shot was captioned with: "And that's a #WRAP !!!!! #pouritupvideoshoot" mentioning the new music video she just finished filming for the song "Pour it up."

The song is heavy on the sexual imagery.

Rihanna mentions stripping and strippers and strippers going down the pole. All in the one song. I wonder if there will be strippers in the music video?

t's not too much of a stretch to imagine Rihanna in a similar situation for the video, especially with this picture.

Rihanna is pictured in a pink thong with lace on the sides underneath--what was merely the outline--of a ripped pair of denim shorts.

Rihann's "jorts" had been shredded almost to nothing, so the thong and Rihanna's incredibly symmetrical booty were all hanging out.

Thankfully, we grabbed a screenshot of the pic because Rihanna quickly took it down from Instagram as an amazed Internet erupted over the sexy picture and Karreuche Tran and Chris Brown's possible response.

Rihanna also uploaded a less revealing pic, but sexy all the same today.

But Chris Brown must have seen Rihanna's earlier Instagram pic and we're wondering if he's starting to second guess all the time he's spending with his other ex, Karreuche Tran.

We can't wait to see what Karreuche posts next as the battle of butts between Rihanna and Tran continues. But with Chris Brown "Stay" with Karreuche after seeing this recent Rihanna pic?