The Big Bang Theory star Mayim Bialik on why Amy and Sheldon's love was so celebrated

When Mayim Bialik joined The Big Bang Theory in season 3 as neuroscientist Amy Farrah Fowler, she had no idea it would become one of the most important roles of the series. But by season 4, she was officially a series regular on the CBS comedy, and her unique onscreen relationship with Jim Parsons' Sheldon Cooper would soon become the heart of the show.

"I think Jim and I both didn't know where this relationship would go," Bialik says in the latest episode of PeopleTV's Couch Surfing. "There was a lot to us not being a sexually active couple but still being romantically and intimately interconnected in so many ways. I would say it's probably the longest-running nonsexual relationship on television, at least that I know of."

Sheldon and Amy's nonsexual relationship became something new when they ultimately "had coitus" for the first time in season 9's "The Opening Night Excitation," and they would go on to get married in the season 11 finale. It was an unexpected arc for both characters considering where they started, as Sheldon was always averse to romance in the early seasons and Amy was only supposed to be a guest star. That's actually why Bialik first auditioned for the role.

"It is true that after I got my doctorate I had an infant and a toddler and I was running out of health insurance," she says. "I had been teaching neuroscience for about five years after getting my degree, and I figured if I could just get a job here or there I would be able to get health insurance. And I had never seen The Big Bang Theory, I didn't know what it was. It was a guest spot, possible recurring role, and that's how I ended up auditioning."

She laughs as she adds, "Then it led to this."

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