B1A4's Gongchan revealed CNU's silliness on Twitter.

The picture was posted on Gongchan's Twitter on the 27th with the caption, "How is he so happy?"

CNU is seen wearing a hoodie and pajama pants. He appears to be dancing with an excited and happy expression on his face.

CNU jokingly responded to Gongchan via Twitter, tweeting, "Please take care of my image!"

Their fans responded by saying, "They're so cute at night" and "CNU seems like a rascal".

B1A4 attended the 15th Annual Korean-Chinese Concert on November 25th.