The second annual iHeartRadio Festival, a two-day affair promising musical names big enough to tear tourists away from the stiff drinks and addictive card games, kicked off on Friday in Las Vegas. No Doubt was given the honor of performing on opening night, bringing a mix of new material from Push and Shove and classics spanning the group's 20-year career. While drooling over Gwen Stefani's hard body and eclectic style, as well as the group's ability to make you move, have become expected over the years, No Doubt managed to pull off a surprise for the crowd when they welcomed Pink onstage for a rendition of "Just a Girl."

As much as she deserves her own accolades for an incredible pop career she's created for herself, Pink recognized her role as a "special guest" in the set, remaining gracious about her opportunity to perform with a band as iconic as No Doubt. As a thank you to her generous hosts, she bowed down in front of Stefani, before quickly going into a few sets of push-ups—as if there was any other option when in the presence of the 42-year-old. Everyone wants to know your workout secrets, Gwen! She then took control of the second verse, ad-libbing with complimentary cursing when appropriate. "But she's the raddest fucking girl in the world, isn't she?" she asked the crowd. Hard to argue with that. Remember: Both these women have birthed a child (or in Gwen's case, two). We're not worthy. Watch below.

We like the sound of this. Have you guys thought about touring together in 2013?