Gwen Stefani song question?

Ok, so I remember this song sung by Gwen Stefani and I can't remember the name of this song. I remember the music video and it's her and there's one part where she's busting open a pinata, and another part where she's putting on makeup, then she's singing in, like, this pile of jewels. Plus, in the middle of the song there's this guy and he's singing in French/Spanish (and I'm pretty sure that its Gwen, but it might have been sung by Christina Aguilera) Thanks to anyone who can help! =)