S2.E11 “The Bath Item Gift Hypothesis” (12/15/08): Leonard begins working with a genius named David who quickly becomes interested in Penny. The two start dating and Leonard becomes jealous. Eventually, Penny finds naked photos of David’s wife on his phone and obviously breaks up with him. Penny gives Sheldon the best gift he’s ever received, a napkin signed and used by Leonard Nimoy. He is stunned and even gives her a big, slightly awkward hug.
