Taylor Swift vs. Miley Cyrus Beef, Twerker Jealous Of Paul McCartney Performance? 'SNL' 40th Anniversary Diss Sparks Boyfriend Patrick Schwarzenegger Fight?

Taylor Swift's one lucky gal - following SNL's 40th Anniversary special on Sunday evening (February 15), the 1989 songstress hopped onstage with Beatles legend Paul McCartney for a phenomenal "All Star" impromptu performance of "Shake It Off" -

Pretty cool! But apparently, fellow pop starlet Miley Cyrus was not amused...

Because she wanted the after-party limelight!

The "Wrecking Ball" twerker sort of threw a fit, according to an alleged InTouch Weekly snitch. The 22-year-old singer started throwing major taunts during the jam session, saying rather hostile things like:

"Her guitar wasn't even plugged in... Those aren't even real chords! She's not even playing!"

Jealous much?

Cyrus supposedly got so upset, she later took out her aggression on 21-year-old boyfriend, Patrick Schwarzenegger. Her behavior got rather immature during an otherwise festive time:

"[Schwarzenegger left and] waited for her at the elevator, but she ignored him and he just left her there," the source explains.

Cyrus did perform at the same bash, but it was rather lackluster compared to Swift's upbeat appearance. The insider claims, "She sang an emotional ballad - it was a buzz kill." Ouch!

Thankfully, Cyrus did better during the actual event - thanks to Paul Simon!

Will Cyrus and Swift become Hollywood's next biggest "frenemies?"

Is it time for the Bangerz superstar to revamp her career once again? Perhaps this kinky "Tongue Tied" bondage clip might do the trick...

[WARNING - EXPLICIT CONTENT]

Cyrus never fails to shock her fans!