We're guessing that Taylor Swift probably wants to know why Rihanna has gotta be so mean. 

RiRi apparently wasn't impressed that T-Swift was singing and dancing in her chair at last weekend's VMAs. According to Us Weekly, Rihanna whispered some rather harsh remarks to the person sitting next to her about Taylor.

“She’s making a scene,” Rihanna reportedly said at the show. “She ain’t cute.”

Whoa! We hadn't heard about these two previously having any kind of beef, so this is definitely a shocker. The only difference we know about them is that they do not feel similarly about Justin Bieber: Taylor is said to strongly dislike the guy, while Rihanna has been rumored to flirt with him at a club recently

This isn't the only controversy surrounding Taylor's appearance at the VMAs. She made headlines when she appeared to mouth to Selena Gomez during the telecast that One Direction  and Taylor's ex Harry Styles  should "shut the f**k up." Nothing subtle about that.

So do you think Rihanna went too far with her comment about Taylor? Or do you think Taylor was at fault for acting at the VMAs like she's the only girl in the world?

Source: Us Weekly via Hollywood Life