Shuu would leap to his feet, swaying his hips and screaming the lyrics with way more passion than appropriate.
He then grabs Hinami and forces her to dance, and her desperation motivates Ayato to stop a wild Shuu.
The wild Shuu then corners Ayato, and soon he’s bopping to it as well.
Even when Touka takes her metal detector out with Miza, she’s singing it. And possibly listening for a groan from Kaneki.
In fact, originally Shuu planned to scare Kaneki out of his kakuja by singing YMCA over the entire dragon.
It was only stopped because Amon would have shot himself if he heard the song again.