The Big Bang Theory (2007)

S9E22 The Fermentation Bifurcation

The group visits a wine bar and unexpectedly bumps into Penny's ex-boyfriend, Zack. Meanwhile, Bernadette finds herself spending the night with Sheldon after she can't join the others for wine tasting, leading to an evening that doesn’t quite unfold as she hoped. Additionally, things take a turn when Koothrappali introduces his new girlfriend, Claire, adding to the night's unexpected twists.