Mariah Carey was killing it at her concert, and then Rihanna showed up in the front row, got all bold, and pulled down her top to flash her boobs. She then asked Mariah to sign her tits, which was totally a wild and hilarious moment.

Mariah: https://www.instagram.com/mariahcarey
Rihanna: https://www.instagram.com/badgalriri/