The Hofstadter Isotope: [s2e20]

Despite being a "nerd," Stuart successfully woos Penny with his artistic sensitivity. Their date goes so well that Penny invites him in for "coffee" (which Penny clearly intends to lead further), but they are interrupted by Sheldon, who engages Stuart in a heated, hours-long debate about who should replace Batman if Bruce Wayne died.

"The Big Bang Theory" The Hofstadter Isotope (TV Episode 2009) - IMDb [S2E20] The Hofstadter Isotope

is the 20th episode of the second season of The Big Bang Theory , which originally aired on April 13, 2009. This episode is a fan favorite because it introduces Stuart Bloom and marks a major shift in Leonard’s pursuit of Penny. Episode Plot Summary Despite being a "nerd," Stuart successfully woos Penny