Olly Murs is well on his way to international stardom. The 'X Factor U.K.' runner up, currently opening for One Direction on tour, clearly gets along with his headliners. Murs did a duet with Niall Horan in a pretty hilarious acoustic rendition of his first stateside single, 'Heart Skips a Beat.'

Murs and his band combine vocals, acoustic guitars and stools to create the acoustic version of the electro-pop tune, and it's just as catchy as the original. Towards the middle of the clip, the camera trails off to the bathroom, where Horan is sitting -- with his pants up, mind you -- on the john, playing guitar.

Horan emerges from the restroom eventually and sings and dances along with Murs, contributing various "skips" to the chorus. Horan's got impressive guitar skills that fans may not see that often, so it's fun to see him with an instrument having fun with his pals.

The acoustic version of 'Heart Skips a Beat' lacks a bit of the touches that made the original so attention grabbing, but it's still pretty infectious. The original hit No. 1 in England last year and earned a BRIT nomination for Best British Single, and the exposure the single will garner from 1D's tour will surely put it on the map on this side of the pond (especially if this video has anything to do with it). Why? Well, after their serenade, Horan closes the video by... well, you'll see. And you'll laugh.

Watch Niall Horan and Olly Murs Duet on 'Heart Skips a Beat'