Darren Criss & Katy Perry: 'Teenage Dream' Duet!
The new Glee star sang an a cappella version of the song with the Warblers before Katy came out and finished the song as a duet with Darren!
“About to do something REAL fun!” Katy tweeted before going onstage.
The Trevor Project is a crisis hotline for LGBTQ youth.
FYI: Darren is wearing a Ben Sherman suit.
Darren Criss, The Warblers & Katy Perry – Teenage Dream