Remember when About a Boy's Will (David Walton) showed up on Parenthood months ago? Crosby (Dax Shepard) is repaying the favor by coming over for a wild poker night! Both shows are produced by Jason Katims, and since they both take place in the San Francisco Bay Area, producers thought it would be fitting if the two musicians knew each other. Even though we knew this was coming, it's still kind of bizarre to see the worlds meshing. The full episode airs tonight at 9 p.m. on NBC!