Britney Spears' new single: 'Perfume'

Britney Spears is baring her insecurities with her new single, "Perfume."

The track was released via Facebook on Sunday, and features lyrics that are more intimate than the robotic commands heard on her earlier dancefloor-ready cut, "Work B***h."

"This is like sharing a piece of my heart," Spears posted on Facebook when she shared the track, leaving fans to fill in the blanks on who she could be singing about. (The 31-year-old broke up with former fiancee Jason Trawick in January, and she admitted to MTV that the breakup wasn't fun but it did give her inspiration for her new album.)

In the ballad, Spears describes using perfume - of which she should have plenty, given how often she releases a new fragrance - to "mark her territory" with a man she thinks may be less than faithful.

"'Perfume' is incredibly special to me because it hits close to home, and I think the story is relatable," Spears told E! News. "Everyone's been through an insecure moment in a relationship that's left them vulnerable, and I think this song captures that."

Spears co-wrote the track with Sia, and its plaintive lyrics are a sign that "Britney Jean" will indeed be a personal journey.

"I poured my heart and soul into this album," Spears told fans in a handwritten open letter. "I've learned a lot about myself, and as I am finishing, I am reminded of the incredible foundation that has supported me for the last 15 years. Thank you all for continuing to follow me on this journey and for allowing me to do what I love to do. I can’t believe this is my eighth studio album and I know I keep telling you that it is my most personal record yet, but its true and I’m really proud of that."

"Britney Jean" is scheduled to arrive December 3.