Rihanna Exchanges Words With Fan at Mariah Carey Concert, on Video

Rihanna was fan-girling a bit too much for another fan during Mariah Carey's concert in Las Vegas recently ... and things got slightly heated between the two.

Riri was lovin' every moment of Mariah's show Saturday night in Sin City with the others in the packed crowd.

Video shows Riri swaying to Mariah's "We Belong Together," waving her arms and blowing kisses to Carey, who was performing the hit song onstage.

Riri was perched on top of a chair, blocking the view of fans behind her. This created some friction between Rihanna and another person, who supposedly told the icon to sit down so they could see Mariah's performance.

The clip captures the exact moment Riri turns and utters a few choice words before getting back into the groove of the music.

Lots of people commented on the video once it was uploaded to social media. One person said Rihanna's celeb status doesn't give her the right to block someone's view. Another praised her for handling the situation with composure.