It's been four years since Ashlee Simpson released her last album, Bittersweet World, but from the looks of her edgy video for "Bat for a Heart," it appears she has done a lot of growing up in between.

Simpson gave fans a sneak peek of her comeback clip on Wednesday. "Happy Halloween! As promised, here's a little tease of what's to come!" she tweeted, linking to a 50-second clip of the single and new music video, which will be released in full on November 21.

In the black-and-white clip, Simpson trades in the good-girl image she established with her debut album Autobiography for heavy eye make-up and tattoos. In the video Simpson is dancing in front of a padded white wall, sings seductively to a handheld camera and shows off some impressive ballerina moves in her underwear.

Yet, what might grab most people's attention are the mature and graphic lyrics that make up this song, which has a dark, bass-thumping pop sound.

"In this tease I do drop the F bomb so you've been warned!" Simpson teased shortly after she revealed the new track. The bomb she's referring to comes when she sings, "I know you want it now/ I'm gonna bang bang, f--- you up/ twist you out inside of my head."

Is the song about her ex-husband, Pete Wentz?

In July, Simpson opened up to Nylon magazine about the sound of her upcoming fourth album, "I'm really proud of the sounds and I'm really excited for it to be an artistic venture. The sound is a little soulful, a little electronic."

A lot has happened to Simpson in the four years since she has released Bittersweet World, Simpson married and divorced Pete Wentz and had her first child, Bronx Mowgli Wentz.

What do you think of Ashlee's new single? Let us know in the comments.