WATCH: Is Britney Spears The Only Celeb EVER To Mime In Carpool Karaoke?

Two Brits, one car.

We really wanted to hear the pop princess croon her biggest tunes, yet it was The Late Late Show host James Corden who belted out the chart hits, as Britney Spears mouthed the words into a water bottle.

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The Toxic singer and 38-year-old comedienne looked like they had a ball as they sang along to Oops!… I Did it Again, Womanizer and Make Me. They even donned the now-iconic Britney high-school outfit for a rendition of Baby One More Time.

The jam session was played during Corden’s chat show and we’re delighted he finally got the singer to hop in the passenger side for his infamous Carpool Karaoke segment.

But, why couldn’t we actually hear her sing? Did Corden forget to write it into her agreement? Was she saving her voice for her Las Vegas Piece of Me residency? Or, were her dulcet tones drowned out by an enthusiastic Corden’s booming vocals? Hmmmm…

That man has a great set of lungs on him.

Corden went on to ask the star what her two children - 10-year-old son Sean and nine-year-old Jayden with her ex-husband Kevin - thought of her dancing in her knickers on stage.

She replied: “I think they know that’s mummy performing. That’s what I’ve done since I was a little girl.”