Are Justin Bieber and Ariana Grande collaborating together on a new track? After teasing fans on Twitter last night, Grande confirms this morning to Ryan Seacrest that yes, the two pop stars are indeed working on a duo together!

Arianators and Beliebers were stunned to read a tweet by Justin Bieber yesterday congratulating Ariana Grande on 'Problem' hitting number one on iTunes and hinting that a studio collaboration is in the works. Bieber posted a photo of the two in studio with the caption: "congrats @arianagrande on your number 1 song.#arianabieberduet ??" (Check out the photo below.)

Later Grande responded with the most-telling tweet of all, writing:

Grande later confirmed to Ryan Seacrest on his radio show this morning that the two are indeed collaborating on a song together.

No details yet have been released about the song including what, when or where but we're pretty sure Belieber and Arianators will be vigorously checking their Twitter feeds every five minutes for updated news about this collaboration.

News of the collab comes just after it was revealed that Grande had recorded a song written by Harry Styles, and the Biebs was working hard in the studio with Austin Mahone. We can't get over all of the amazing pop star collaboration news!

Are you excited to hear what they have in store for us?