If you ever wanted to hear Russell Crowe sing about balls in your mouth, well, here you go.

The notoriously volatile actor was in a happy-go-lucky mood when he stopped by The Tonight Show Starring Jimmy Fallon on Earth Day (April 22), though really it's impossible to be anything but completely blissed out when you're in the presence of Jimmy Fallon. And especially when you're singing about balls — tar balls, that is.

In honor of Earth Day — and the huge BP oil spill that occurred five years ago — Russell and Jimmy decided to pay tribute to the lovely effects of the spill and sing about tar balls getting in your mouth while swimming.

"The oil spill by BP has left tar balls all over the sea," Jimmy sang as he strummed on his guitar. "So don't go swimming down in the south unless you want tar balls in your mouth."

"Balls in your mouth, balls in your mouth / Don't swim in the ocean, you'll get balls in your mouth," Russell chimes in on the acoustic guitar, leading both men to belt out the refrain multiple times. Go for the gold, Jimmy Fallon and Russell Crowe. For that gold.

While the duet is basically everything we could have ever wanted from a Jimmy Fallon/Russell Crowe song about getting balls in your mouth, the only thing that would have made it slightly better would be if Russell sang it in the style of his Les Misérables character, Inspector Javert. But hey, we'll take what we can get.

Check out Jimmy Fallon and Russell Crowe's epic duet in the video above.

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