After five years of waiting, Amy Farrah Fowler and Sheldon Cooper finally did the deed in a monumental moment in The Big Bang Theory’s history.

The couple’s first time coincided with the rest of the gang seeing Star Wars: The Force Awakens on opening night while Sheldon planned a special night for Amy’s birthday on the E4 comedy.

After presenting his possible birthday plans to Penny and Bernadette: a private harp concert by the LA Philharmonic, a sheep festival, and sex, he decided there was only one real choice. “Amy’s birthday present shall be my genitals,” Sheldon declared.

Jim Parsons and Kaley Cuoco (Michael Bulbenko/Paley Centre)
Kaley Cuoco joked with the rest of the cast at PaleyFest (Michael Bulbenko/Paley Centre)

Speaking at a celebration of the show at TV festival Paleyfest in Los Angeles, Jim told Mayim he enjoyed the chance to get between the sheets: “It felt right. Everyone else has done bedroom scenes but I had never done pillow talk in nine years and then all of a sudden I was in bed with you, I can’t wait to be back in bed again!”

Mayim Bialik and Jim Parsons of The Big Bang Theory at PaleyFest LA 2016 honoring The Big Bang Theory
Jim Parsons and Mayim Bialik on stage at PaleyFest (Michael Bulbenko/Paley Center)

Mayim said: “We were joining the club of all of humanity.”

She added: “Neither Jim nor I thought it was happening. We get the scripts the night before a table reading and I couldn’t believe it.”

The Big Bang Theory cast and creative (Rob Latour/Paley Center
The Big Bang Theory cast come together (Rob Latour/Paley Center

Johnny Galecki, who plays Leonard on the show, also dropped some major casting news at the event.

He said: “We were all honoured to be invited to this James Burrows tribute and we had the opportunity to meet the casts of the shows he directed and I met Judd Hirsch.

Judd Hirsch (Jimi Celeste/AP)
Johnny Galecki revealed he was a big fan of Judd Hirsch (Jimi Celeste/AP)

“I ran up to him and bombarded him with what a fan I am. I should preface this story with the fact they were serving wine at this event, it was free wine.

“I went off for a bit but this is true, when we were shooting the pilot I watched the first two season of Taxi, not because I was basing the character on him but the idea that he was the anchor but was just as confused as everyone else.

Johnny Galecki signs autographs for fans (Michael Bulbenko/Paley Centre)
Johnny Galecki revealed some major casting news to fans (Michael Bulbenko/Paley Centre)

“I said: ‘Hey, would have you any interest in playing my dad on the show?’ It may have been a little presumptuous but it went from there. I can’t wait.”

The Big Bang Theory airs on E4 on Thursdays.