Todrick Hall can't stop gushing over his mega-talented, "genius" friend, Taylor Swift!

The 32-year-old YouTube star stopped by ET for a Facebook Live interview on Tuesday to talk about his partnership with "Positively Fearless," a movement promoting HIV education among African Americans and Latinos. During our interview, he also shared behind-the-scenes secrets from the filming of Swift's "Look What You Made Me Do" music video.

WATCH: Taylor Swift Is Breaking Records All Over the Place With 'Look What You Made Me Do'

Hall is one of the dancers featured in the epic video, which made its debut over the weekend during the MTV Video Music Awards. Hall can be seen to the immediate left of Swift starting at the 2:12 mark, rocking an "I <3 T.S." crop top, a nod to the pop star's famous ex-boyfriend, Tom Hiddleston, who wore a similar shirt during Swift's Fourth of July bash last summer while the two were still dating.

Y'all... Taylor Swift really slayed all the past versions of herself in the #LookWhatYouMadeMeDo music video. #VMAspic.twitter.com/6c1LLcWM3B — Entertainment Tonight (@etnow) August 28, 2017

"That is the first and only time you'll ever see me in a crop top," Hall joked to ET's Denny Directo. "I had no idea that's what I was going to be wearing. I was super into it, but I was very nervous. I've never done anything like that in my entire life."

"I just thought [the idea for that section] was brilliant," he added. "She's just such an iconic and epic person, and whatever she puts her hands on always turns to gold. I love the fact that she expresses how she feels through her music as opposed to on Twitter, on social media. It's always done in such an epic and creative way. I just really appreciate any artist that does that."

Hall -- who actually met and became friends with Swift years ago after she stumbled upon one of his YouTube videos -- revealed to ET that he was sworn to secrecy once he heard about the project.

"We became BFFs, and then she called and said, 'I'm working on this project that's super secret but I know I can trust you. Will you not tell anyone?'" he recalled. "And I didn't tell anyone. It was the best! It felt like Christmas came early because when it came out my phone blew up more than it ever has before. Everybody was freaking out about it. It's such an epic and iconic video to be a part of."

"I think it was shot in May," he continued. "And it was a huge secret to keep and it was very difficult … It speaks volume of what type of person Taylor is, that she could have all those people on set and then it not leak. People really respect her, she treats everyone so well. And I don't know if I'm supposed to say this, but on the day that it came out, she sent everybody these beautiful bouquets of flowers and said, 'Thank you so much for being a part of this and keeping it a secret,' because it just made it so much more epic."

Although he "didn't know very much about" the video before filming began, it was a project he couldn't pass up.

"I understand why she wasn't able to tell me a lot because it was a huge project so close to her and she filmed it so much before it came out," he said. "So, I respected that and completely was like, 'I trust that you're going to put me in a positive light and that the video is going to be amazing.'"

MORE: Victim or Villain? Why Taylor Swift Is Battling Her Old Selves in ‘Look What You Made Me Do’

The video also features a dance break with Hall, Swift and the rest of the backup dancers, beginning at the 3:05 mark. Hall confirmed to ET that he didn't have anything to do with the choreography -- the dance was created by Swift's longtime choreographer, Tyce Diorio, the mastermind between her moves in "Shake It Off."

"I was so impressed because, no shade to other people in the industry, but there are a lot of people who try to dance, but with her, it seems very natural," he said. "We've had a lot of experience, Taylor and I, dancing at the clubs, so I knew she had what it took. But sometimes it's difficult to translate your club dancing to your on-camera dancing, and I thought she did such an amazing job."

"She was so kickass," he continued. "And we didn't film it that many times, she just killed it every single performance. I mean, I've worked with Beyonce and I've gotten to work with Taylor and it was a very similar thing. She's a perfectionist -- she was never going to go out on camera and not show herself in the best light. I thought she was amazing. For your first time ever dancing? That looks like she's been dancing her entire life."

Simply put, Hall couldn't be more proud of his pal.

"I love the fact that she takes so much pride and appreciates the art form that is dancing and what we do and wanted to make sure that her dancing was at the same level as the dancers," he gushed. "She accomplished that. I'm so proud of her."

"Taylor is definitely raising the bar, everybody else better take note," he added. "I'm just proud of her because she's such an amazing person on the inside and out. She's treated me so kindly … I've never seen her be anything less than an angel. She's like a living, breathing Cinderella. So, it's really cool to just watch her shine like that."

As for all those secret messages in the video? Well, looks like fans will have to continue speculating on what they all mean on their own.

"I'm not sure what the message she's trying to get across is, I don't necessarily wanna speak on that, but I just think that whatever it is she's trying to get across, she's saying it through her music and her lyrics, and it's all metaphoric, so that it can be open for interpretation," he shared. "I just think it's so genius! I'm so inspired by her, and when she says, 'Look what you made me do,' she means, 'Look what you made me do… you made me break records, you made me sell more records than anyone else' … it's just really insane."

Before the interview ended, Hall also opened up about all those Beyoncé "Formation" comparisons.

"I am a huge Beyoncé fan, I'm like a chair board member of the Beygency," he explained. "I wasn't concerned because I knew what was to come and I knew that there was nothing even [remotely] Beyoncé -esque about the actual performance."

"Beyoncé did not invent lines or standing in lines," he continued. "I think that what we did was really cool of just image … that was Lemonade, this is kinda just like soda pop. It's different. They're both great drinks, but different drinks."

WATCH: Taylor Swift's Epic 'Look What You Made Me Do' Music Video, Decoded!

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