For all of you LR fans out there, like me!, this is awesome. Leo is rapping Ravi's part, and Ravi sins Leo's part in Beautiful Liar.
The video belongs to Lee Hongbin on YouTube.
There is subtitles but not a lot for the English speakers.
*Bonuses of video: 1) Leo smiles, 2) Ravi gets embarrassed, 3) Potential fangirling
BONUS VIDEO FANGIRLING WIIIIIIILLLLLLLL HAPPEN!!! YOU HAVE BEEN WARNED!!!!!!
video credit to Lee Kpop on YouTube