George Takei has revealed why there wasn’t LGBTQ representation in the original series of Star Trek.

The original series of Star Trek, which aired from 1966 to 1969, was groundbreaking in many ways. Part of this strength came from the diversity of its cast, and how it also featured one of the most prominent on-screen interracial kisses at the time.

However, one thing the show never featured was LGBTQ representation. George Takei, who played Mr Sulu on the show, told PBS NewsHour that he pushed for there to be an LGBTQ character on the show.

Unfortunately, show creator Gene Roddenberry had to turn the idea down. Recalling what Roddenberry had told him, Takei said: “I’d like to do that, but he said ‘I’m walking a tightrope.’ The interracial kiss was very controversial.”

Although the original Star Trek series didn’t contain an open LGBTQ character, years later it was revealed that Takei’s character did have a male partner. And a same-sex couple was introduced in the series’s most recent iteration, Star Trek: Discovery.

In 2018, fans were outraged after one of the couple, Dr. Hugh Culbur, played by Wilson Cruz, was killed by sleeper agent Lt. Ash Tyler. However, in an episode broadcast on Valentine’s Day, the series delighted viewers by resurrecting Dr. Culbur and reuniting the couple.

And Anthony Rapp, who plays Lt. Paul Stamets, confirmed in an interview that the couple’s relationship wasn’t over. “We’re still in the midst of it,” he said at PaleyFest. “Things are continuing to evolve. We’re grateful we’re given something authentic and complicated [by the writers].”

Wilson also opened up about the response he’s had from fans since starring as part of the show’s first same-sex couple, and praised his co-star and on-screen lover Anthony for being an “incredible” actor.

“It’s been really moving to me. I am the luckiest man in the world,” he said.

“To have been on the show and then brought back to it? It’s life-altering and to do it with that incredible actor who I’ve known for 22 years is a gift that I don’t know that I can ever repay back.”

Related: 34 of the best LGBTQ shows you can watch right now on Netflix