A clip of Luhan serenading his co-star Yang Mi during the filming of 'The Witness' was shared online, letting you listen to his sweet croonings! 

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Luhan is heard singing "Ch�ng Er F?i" (or "Flying Fireflies"), as he slowly walks up to Yang Mi, with what looks to be a ukelele snuggled close to his stomach. After he finishes his serenade, Luhan smiles bashfully and fiddles with the ukelele, trying to teach himself the chords to the song. He even utters a few words in Korean near the end, asking a Korean crew member, "I only have to play this part, right?" 

Check out the video above and give a listen to Luhan's mesmerizingly sweet voice! 

Tip: babylu