As you were in Cyno's concert and his group band, you were cheering for them

A random man walked towards you and was trying to harass you and ask weird questions.

When Cyno continued to play his electric guitar, he noticed you were being harassed

So he played a loud boom to get his attention, which was also a threat to leave you alone

The man got scared and ran off, and Cyno continued to play with his band, feeling disturbed that some guy tried taking you away from him