Season 2, Episode 16 - The Cushion Saturation
Aired March 2, 2009
Sheldon's world is turned upside down when Penny damages his "spot" by accidentally shooting a paintball gun at his prized couch cushion. Penny and Leonard struggle to help a difficult Sheldon through this testing time. Meanwhile, Wolowitz and Leslie Winkle start dating after a paintballing encounter of their own.