TBBT 4A Apartment.
The forbidden topic ultimately came to nothing.
It was not because Howard was particularly loyal... he and Sheldon could barely be considered friends, constantly sniping at each other.
If Leonard had not been between them, they would have stopped speaking to each other long ago.
The reason Howard ignored Sheldon's forbidden words...
Was because he himself was a disgrace to Jews, having done far too many things that violated religious doctrine.
The pot calling the kettle black.
While Leonard worried about the beautiful, intelligent child he and Penny might have, he began racking his brains to write an apology letter.
Then, something that delighted him happened. He had just slipped the apology letter into Penny's apartment when the door opened.
Penny had forgiven him too.
"So, you know Dr. Adam Duncan?"
Penny walked back into Leonard's apartment and impatiently asked the question that had been gnawing at her.
"No."
Leonard first gave an answer that surprised her. Then he grinned, lifted his chin slightly, and looked immensely proud.
"Adam is my best friend, and Sheldon was Adam's high school classmate. We do not merely know him!"
"Wow, cool!"
Penny could not help exclaiming. Even the way she looked at Leonard changed.
"What is so cool about that?"
Sheldon said disdainfully, "Adam is not Adam Warlock!"
"Adam Warlock?"
Penny was a little confused.
"A superhero from Marvel Comics. He is an artificial human who eventually took charge of the Living Tribunal..."
Leonard launched into an endless explanation, but when he caught Penny's gaze returning to normal, he immediately snapped back to his senses and awkwardly waved his hand. "None of that is important..."
"You guys..."
Penny's gaze swept from the embarrassed Leonard to the haughty Sheldon, the lecherous Howard, and Rajesh, who might as well have been invisible.