The Wanted Karaoke + Beer = Goo Goo Dolls

3/25/2012 4:35 AM PDT

Breakout British boy band The Wanted has violated the ONE rule of alcohol-fueled karaoke night -- YOU CAN'T ACTUALLY BE GOOD AT SINGING ... and TMZ has the video proof.

It all went down at Rock & Reilly's Monday night in Hollywood ... the boy band -- known for their new hit "Glad You Came" -- grabbed the karaoke mic and belted out the 90s classic song "Iris" by the Goo Goo Dolls ... and damnit ... it was way too good.

Why they weren't immediately kicked out afterwards, we have no idea.