As the 27-year-old actor told ET at the film's Los Angeles press day on Sunday, he didn't properly introduce himself to Smith on the first day of shooting the Disney remake, leading the superstar to think he was just a dancer on the film.
As Smith tells it, he didn't just think Massoud was a background dancer -- he thought he might have a "security situation" on his hands when Massoud walked into Smith's conversation with director Guy Ritchie.
"So what happened, we're on set and you know, there's 200 dancers standing around and I'm talking to the director," Smith told ET's Kevin Frazier at the Aladdin world premiere in Los Angeles on Tuesday, while Massoud jumped in, blaming the mix-up on Ritchie.
"This dude just comes up and he's like, standing in our conversation. And I'm like, 'That's a bold-a** little dancer going to stand there in the middle of the director and the Genie in this conversation.' And he just stood there and he didn't say nothing!" the 50-year-old actor recalled. "He just smiled and then walked away!"
Massoud eventually came back after realizing the awkwardness of the situation. "I came back and reintroduced myself," he said.
"It was feeling like a security situation, you know," Smith joked. "Like, imagine we're talking and he just did [came up and stood here]. That's weird!"
It's nothing but love between the co-stars now, who hilariously checked out each other's flashy ensembles on Tuesday's red carpet.
"This is a little late night Genie vibes," Smith said of his patterned suit. "I was just feeling sexy by myself. Am I doing too much? Be honest, because I trust your judgment. ... but take a good look. How do you feel about that?"
Frazier cracked that he'll let Smith revisit his outfit choice himself in a year, but definitely had the swagger to rock the bold suit.
"You know what? It's not about the clothes. It's about the inside. Like, you gotta exude the clothes, hot. You can put the clothes on, and then you gotta exude 'em hot," Smith insisted.