CBS

Season 6: Episode 5 - The Holographic Excitation

The Holographic Excitation: In a Halloween themed episode, Sheldon and Amy disagree over ideas for a couples costume for the party Stuart and Koothrappali are hosting at the comic book store. In the end, they compromise, going as Raggedy Ann and Raggedy C3PO. Wolowitz is back from space and won't stop talking about it, which drives his wife and all of his friends crazy. Bernadette confronts him about it and he gets dejected, feeling that everyone is belittling the greatest accomplishment of his life. If he stops talking about space, he's worried he'll just be plain old Howard Wolowitz. Bernadette tells him that regular Wolowitz is perfect for her. Meanwhile, Penny goes to visit Leonard at his lab and ultimately gets turned on by watching him work, resulting in them having sex almost every time he starts talking about science around her.