Five Best Lines - 'The Big Bang Theory' - 12/17/2015

After more than five years of dating, Sheldon and Amy spend their first night together. Also, Leonard, Wolowitz, and Koothrappali must decide who will take their extra Star Wars movie ticket in the episode entitled "The Opening Night Excitation."

"But someone may spoil the movie. No one can spoil Amy's birthday for me. Surprise! She's even older! No one saw that coming."

--Sheldon's explanation of why he wants to see the opening night of "Star Wars" rather than celebrating Amy's birthday.

"For future reference, if I want to watch 'Mean Girls,' I'll stream it on Netflix."

--Penny and Bernadette torture Sheldon a bit while he's standing outside Penny's apartment.

"It's like going with your Grandpa. Instead of eating popcorn he brings little pieces of chicken in Tupperware and a thermos full of soup."

--Howard's reaction to the idea that they give Stuart the "Star Wars" ticket Sheldon no longer needs.

"Then it's settled. Amy's birthday present will be my genitals."

--Sheldon tells Penny and Bernadette he is planning to have coitus with Amy.

"I'm going to stay positive. We talked, I told him what women like and after he stopped giggling, he seemed pretty sure of himself."

--Penny seems sure Sheldon will go through with his birthday plans.