They've got this co-parenting thing figured out!

Nicole Richie got all bundled up to catch a flight out of LAX yesterday, so she must be heading to colder temperatures, but husband Joel Madden stuck around L.A. to take care of daughter Harlow and son Sparrow.

We're still waiting to see this married pair out on the town with Joel's twin brother Benji and his girlfriend Cameron Diaz! The Candidly Nicole star and Cammy D are good friends, so we have a feeling the reality star might be putting some pressure on her brother-in-law to pop the question to the A-list actress.

On a totally unrelated note, someone needs to tell the Good Charlotte rocker to pull up his pants!