Penny's 'Big Bang Theory' Secret: You'll Never Know Her Last Name, Steve Molaro Says

We may know all about Penny's (Kaley Cuoco) romantic entanglements , but there's one thing we'll never know: Her last name.

In an interview with Vulture , "Big Bang Theory" executive producer Steve Molaro said viewers should give up hope of ever finding out her last name.

"What name could we possibly pick that would be satisfying at this point? You know, I don't think we will [reveal it]," Molaro said. "We're kind of a superstitious lot here. We've made it this far without knowing Penny's last name. I think we're good not finding out."

The "Big Bang Theory" season finale presented Penny and her boyfriend Leonard (Johnny Galecki) with quite the obstacle when Leonard was offered a job that would leave him on a boat for four months.

"The obstacle is Penny and Leonard have never been better," Simon Helberg, who plays Howard Wolowitz, said. "So, is he really going to leave her for four months?"

But everything worked out, and the lovebirds decided to stay together, because Penny was nothing but supportive.

As for her last name, unless she eventually takes Leonard's, that will remain mystery.