Rainbow's Hyunyoung engaged in a very bizarre show of fan service at a recent concert.
In a video clip posted on Koreaboo, Hyunyoung walks up to her group member and points to her inflated cheeks.
She then stands in front of the cheering audience and sprays a huge mouthful of water at them to the surprise of her groupmates.
One even runs over to chide her for what she did.
The fans however, seemed to love the silly prank and the energy at the concert went up.
Check out the clip below.