Preparing for childbirth has been likened to training for a marathon — if only long-distance race training was this funny! Tina Fey and Amy Poehler's look at baby prep class in Baby Mama had experienced mamas doubled over in laughter. Now it's Jessica Alba and Jimmy Kimmel's turn. While a very pregnant Jessica Alba may be planning another hypnobirth when she welcomes Honor's new brother or sister, in a skit that aired on last night's Jimmy Kimmel Live, she asked the late-night talk-show host to fill in for her absent husband at a birthing class at LA's The Pump Station. Wearing an "empathy belly" and volunteering to demonstrate birth, Jimmy and Jessica add some life to the typically boring class curriculum. Check it out!