rihanna topless pic!

Rihanna is one sexy exhibitionist!!

The 24-year-old posted this topless photo on Twitter along with the following: "Where have you been all my life?!"

The "What's My Name" songstress has recently been in an online feud with ex Chris Brown's girlfriend Karrueche Tran.

After Rihanna took a dig at Tran Tweeting "Ima make u my b**ch" ... Tran Tweeted, "I'm Angeline [sic], you're Jen. C'mon you see where Brad is at."

Yikes! Sounds like fighting words.