Strange but true: Pop star Christina Aguilera has cut a duet with Blake Shelton, her fellow coach on The Voice, for Christina's upcoming album.

The track is called "Just a Fool," and it appears on Christina's album Lotus, due Nov. 12, according to several music industry publications and a track listing on amazon.com's United Kingdom site.

It all started last season when Christina sang Blake's hit "Hillbilly Bone." Blake tweeted he was speechless, and Christina tweeted back: "Now we need to team up for a country duet Blake!! I'm down!!"

And that led Blake to declare, "Well, you know it’s an understatement to say that I’m open to singing a duet with Christina Aguilera. More like I would pay her, I would beg her, I’ll wash her car, I’ll clean her house, I’ll babysit her kid . . .  I’ll do whatever I need to do to get that done."

No word whether Blake's done washing her car yet.