They're on … they're off … it's on … it's off … we're talking about Miley Cyrus, Liam Hemsworth, and her engagement ring, of course.

Cyrus, 20, just dropped her single "We Can't Stop" on Monday, and X17 photographed the singer on set filming her new music video sans her engagement ring (again). So, what is the latest with Cyrus and Hemsworth?

Sources tell omg! that the couple of four years are "still together" and still living together at Cyrus's home in the Toluca Lake neighborhood of Los Angeles's San Fernando Valley. However, the same insider adds the two "are not actively planning their wedding."

"She is going to be working like crazy," adds another source. Cyrus has not been shy about saying she has put this album before everything and everyone else.

Cyrus may have been spotted without her ring Monday night on set, but she was wearing it while making promo rounds all day yesterday. Hey … twerking with a 3.5 karat ring can be hard! Guess we just shouldn't expect the sparkler to show up in the music video for her summer party anthem "We Can't Stop."

Since Cyrus and her "Catching Fire" beau will be apart again when she heads across the country to promote her new single, it's likely the split rumors won't be dying down anytime soon.

Guess we'll just have to allow Cyrus's ring finger do the talking … when she's not shooting a music video, that is.