"They decided it wasn't working," a source close to the couple tells PEOPLE. "They're moving on."
Willis, 22, whose famous mother Demi Moore and stepfather Ashton Kutcher have been under fire for relationship woes of their own, seems to be bouncing back just fine. On Saturday, she headed to Tao in Las Vegas where last year she celebrated her 21st birthday.
The Hollywood royalty hung out with Glee's Mark Salling and his pal Chord Overstreet, who appeared on the hit show as well.
"Rumer was bouncing around the club having a great time just dancing," says an onlooker.
And proving she's not dwelling, "Chord was flirtatious with Rumer," says a source. "They had a lot of fun."