Sheldon: You would never make me kiss you, then say I love you, then break up with me.
Leonard: I wouldn't.
Sheldon: You know why? Because you're a man. The champagne of genders.
Leonard: I may be a man, but I think I'm the one that screwed up on this one.
Sheldon: And you admit it. Like a man. All your hear woman say is "I'll have a salad", "Where's my lip gloss?", "I think this element should be called radium."
That last one was Madame Curie.
Leonard: I figured that out.
Sheldon: You know what? She was sort of an honorary man. She had a penis made of science.