Penny: What'd you say to her?
Sheldon: Well, I just asked her if I should start watching the new Flash TV series.
Penny: And that made her angry?
Sheldon: Baffling, right? We were necking like a couple of hooligans under the school bleachers. I stopped so I could ask the question. Next thing I know, good-bye, kissy face. Hello, yelly face.