Kesha has a new song about her vagina.  Here's something you wouldn't expect to hear:  She co-wrote it with her MOM.

The song is called "Gold Trans Am", and it's on the deluxe version of her new album "Warrior". 

She says, quote, "We write songs about boys and sex together.  That may not be normal to the average psychiatrist out there but I think it's pretty cool . . . Don't analyze.

"That's the problem with so much culture out there.  People are so trapped into trying to do the right thing.  As long as you are not hurting anyone I think you should feel free to indulge your fantasies."

The song was originally supposed to be about Kesha's CAR . . . but that changed.

 She says, quote, "It began as a song about my car, which is a gold Trans Am, and it works about 40% of the time.  I don't have another car because I love that one so much.

"But then like all great pop it became a metaphor for something else:  my [kitty].

"But my vagina is in tip top working order.  Valeted and souped-up and working 100% of the time."

Check out the song below!