After doing dinner with Taylor Swift at Giorgio Baldi in Santa Monica, Rihanna changed her outfit (but not her blonde wig) and stopped by MyStudio in Hollywood at 1:40am.

The 24-year-old R&B hottie left with several friends just twenty minutes later, and we're not sure why, but we're guessing she got wind of the fact that ex-boyfriend Chris Brown and ladylove Karrueche Tran were just a few doors down at SupperClub on Hollywood Blvd. Chris, who appeared to be in a great mood, left the hotspot with Karrueche and all of her friends, and he even stopped to purchase a bouquet of roses for his main squeeze on the way out.

Rihanna probably would have flipped if she saw this going down -- good thing she left early and avoided a confrontation!