(CNN) -- Most people need encouragement to remove their clothing. For Justin Bieber, boos from the crowd will do just fine.
The 20-year-old singer stripped down to his skivvies at 2014's "Fashion Rocks" event on Tuesday night in Brooklyn, where he was greeted with a negative reaction from some in the New York audience.
As Bieber took the stage with model Lara Stone to introduce singer Rita Ora, there were some noticeable jeers mixed in with cheers.
The singer seemed unfazed by those who weren't pleased with his appearance at the show, turning to Stone and telling her that he doesn't "feel comfortable unless I'm in my Calvins."
"Calvins" as in his Calvin Klein underwear, which he proudly showed off to the increasingly enthusiastic crowd.
"Grandma always said kill 'em with kindness," Bieber tweeted. "And then strip on live national tv. Lol."
According to Bieber's Instagram, his striptease was impromptu. "Just stripped on national television hahahaha it wasn't planned lmao," he shared with his fans.
If nothing else, it seems Stone approved.
"Thanks for that @JustinBieber," the Dutch model posted to her own Instagram account.