Jimmy Fallon donned the mom wig once more on Thursday's Tonight Show for the "Evolution of Mom Dancing Part Two." First Lady Michelle Obama ? on set promoting her Let's Move kids fitness initiative's "Gimme Five" challenge ? joined the host to summarize the most awkward and hilarious maternal grooves in history. During the performance, Fallon takes a cheap shot at the Commander-in-Chief with the awkwardly proper "Barack Obama," but the First Lady returns the favor with the nerdy pointing of her " Jimmy Fallon." The duo's first "Evolution of Mom Dancing," from a 2013 episode of Late Night With Jimmy Fallon, became a viral video hit thanks to mom-tastic moves like the "Happy Snapper," the "Out of Sync Electric Slide" and the "Just the Hands Part of Single Ladies."??