Katy Perry enjoyed Glee's cover of her song so much, she decided to add her voice to the song.

At a benefit this weekend for The Trevor Project, the leading national organization focused on crisis and suicide prevention efforts among lesbian, gay, bisexual, transgender and questioning (LGBTQ) youth, Perry joined Glee's Darren Criss and the rest of Dalton Academy's Warblers for a live performance of "Teenage Dream."

Watch the clip above and let us know what you think. Do you like hearing the song with Katy only, the boys only or with all of them?