Well now we know what that the “big bang” in the title is referring to.

After more than five years of dating, Sheldon and Amy had sex on Thursday night’s episode of The Big Bang Theory.

The episode cleverly juxtaposed Sheldon and Amy’s first roll in the hay with the opening night of Star Wars: The Force Awakens, another pop-culture event that has been built-up with years of anticipation and finally, uh, came on Thursday night.

Sheldon, Leonard, Wolowitz, and Koothrappali all purchased opening-night tickets in advance, but that was when Sheldon and Amy were broken up. Now that they are back together, Sheldon is facing a socially obtuse nerd’s Sophie’s Choice. Star Wars opening night and Amy’s birthday fall on the same day. What is he supposed to do?

“My friends are telling me I shouldn’t abandon my girlfriend on her birthday to see the new Star Wars movie,” Sheldon tells Bob Newhart’s Arthur, appearing to him in a night vision dressed as a Jedi master. “Sounds right.” Arthur tells him.

With that settled, Sheldon now must pick out a gift for Amy. He goes to Penny and Bernadette for advice, presenting them with two ridiculous ideas. The third option: “I have coitus with her.” Penny is so shocked she shatters her wine glass with her hand. You might have, too, if you didn’t catch wind of CBS’s press release hinting that this was coming.

“Then it’s settled,” Sheldon says. “Amy’s birthday present will be my genitals.”

Before the deed happens, Amy and Sheldon are given a quiet scene together, in which they are adorably nervous. “I’m really nervous,” Amy says. “I’ve been waiting for this for so long. I just built it up in my head. I don’t know what to expect.” Sheldon’s surprisingly tender reply: “Neither do I. But we can find out together.”

The running B-plot of the Star Wars premiere has its pay-off here, with Leonard, Wolowitz, and Koothrappali essentially replicating that dialogue word-for-word as they wait in their seats, a mix of nerves and excitement, for The Force Awakens to begin.

And how was Amy and Sheldon’s first time? “Well I enjoyed that more than I thought I would,” Sheldon says post-coital, the camera panning to Amy and her sex hair.