Who knew that Robert Rodriguez's blood-soaked knife-fest 'Machete' would be the inspiration for the fourth 'Spy Kids' movie?

The director told Moviefone that seeing Jessica Alba's attempts at handling her baby's "exploding diaper" while filming the cult hit sparked the idea for a spy mom with an infant in tow. Alba herself, who had her second baby days after this interview, agreed it's hard juggling movies and mommyhood at the same time.

We also sat down with 'Spy Kids 4' stars Jeremy Piven, who had a blast playing multiple characters; new kids Rowan Blanchard and Mason Cook; and 'Spy Kids' veteran Alexa Vega, who told us returning to the franchise was "surreal" and that, yes, she still gets recognized as Carmen Cortez. Joel McHale also shared an Aroma-Scope (the scratch-and-sniff card being provided during all screenings) secret with us: "My character smells like lavender." Okay, that's not one of the odors available on the Aroma-Scope card, but nice try, funny guy.