The Big Bang Theory Season 12 Episode 12
Overview
Penny’s ex-boyfriend, Zack, and his wife want a baby, but when Zack is infertile, they ask Leonard for help. Also, Koothrappali attempts to mend things with his ex-fiancée, Anu.
Director: Mark Cendrowski
Guest Star: Brian George, Brian Thomas Smith, Chip Chinery, Lindsey Kraft, Rati Gupta, Shay Ali