Twenty-eight-year-old O'Shae Sibley was “living his best life” before a Brooklyn teen fatally stabbed him, a prosecutor alleged on Monday in opening statements at the trial of the accused killer in Brooklyn Supreme Criminal Court.

Sibley, a Black, gay, professional dancer from Philadelphia, had rented a car with four of his friends on July 29, 2023, and spent the day celebrating one of their birthdays at an LGBTQ-friendly beach in New Jersey, Senior Assistant District Attorney Sarah Jafari said. They stopped at a gas station on Coney Island Avenue in Midwood on their way home to Brooklyn.

As they refueled and danced to Beyoncé outside the car, the friends encountered a “hateful” verbal assault of racist and homophobic slurs from a group that included then-17-year-old Dmitriy Popov, who had been working in a smoke shop nearby, Jafari said.

The verbal altercation turned deadly when Popov pulled a knife from his pocket and stabbed Sibley in the torso.

Popov, 20, faces charges of second-degree murder as a hate crime, criminal possession of a weapon and several other crimes. He could spend up to 25 years to life in prison if convicted of the most serious charge. The Brooklyn district attorney’s office is trying him as an adult.

Popov’s defense attorney, Mark Pollard, argued Monday that his client was acting in self-defense. He described Popov as a “frail, skinny, puny” teen facing a group of “strong, in-shape” men. The attorney also said Sibley hit Popov.

“This is about a few terrifying seconds in the life of a 17-year-old boy — not man,” Pollard said, adding: “He was afraid for his life in a chaotic situation.”

But Jafari said Sibley was targeted because he was an “out and proud” Black, gay man, dancing in a bathing suit.

“You cannot kill someone because you are offended,” she told jurors. “You cannot kill someone because how they live their life is not in line with what you think is right.”

Sibley’s loved ones filled several benches in the 20th-floor courtroom — many of them dressed in black. His mother occasionally dabbed her eyes with a tissue during opening statements. One man hunched over in his seat and gasped for breath.

A handful of Popov’s relatives sat behind the defendant on the other side of the courtroom. Popov sat quietly next to his attorney, wearing a white, button-down shirt and navy blue pants. At one point, he jotted down notes on a yellow legal pad.

Jafari described two alternate worlds playing out half a block apart just before Sibley’s death. At the gas station, she said, Sibley and his friends were in their bathing suits, enjoying a beautiful summer night. It was the summer of Beyoncé’s “Renaissance” tour, and the group was dancing to her music.

“They were expressing themselves,” she said.

Popov and his friends were working at a smoke shop down the block, huddling around a screen to watch “half-naked men” wrestle in an Ultimate Fighting Championship match, the prosecutor said.

When the group noticed Sibley and his friends dancing, they decided that this type of behavior in their neighborhood was not OK and walked over to the gas station to confront them, Jafari said.

When the two groups collided, the tension quickly escalated, according to the prosecutor. The group from the smoke shop called Sibley and his friends racial slurs and told them to “get the f—k out of here,” Jafari said.

“We don’t do that s—t. We’re Muslims,” someone said, according to the prosecutor.

One of Sibley’s friends, who was only wearing a jock strap, ran back to the car to put on shorts, Jafari said. Sibley approached Popov, and his friends apologized for making them uncomfortable, the prosecutor said. But the group from the smoke shop kept cursing and telling Sibley and his friends to leave. Popov recorded on his phone.

A clerk at the gas station came outside to defuse the situation, and for a moment it seemed like the argument was over, Jafari said. Both sides walked away, except for Popov, who continued to call out insults and slurs, she said. Then, the prosecutor said, Popov reached into his pocket, hunched over and pulled out a knife.

“Come on, get stabbed,” he said, according to Jafari.

Sibley stepped toward Popov with his palms open, positioning himself between the knife and his friend, the prosecutor said. The teen stabbed Sibley in the torso, slicing five-and-a-half inches into his body and puncturing his heart, Jafari said.

Popov went back to the smoke shop with the bloody knife, rang up a customer and then fled in a car, she said. Meanwhile, Sibley lay on the ground, his pink bathing suit turning red. He was pronounced dead at Maimonides Hospital shortly after.

Popov’s defense attorney said video of the incident would make clear that Sibley and his friends were pursuing his client, not the other way around.

“His perception at the time was fear,” Pollard said.

But Jafari said Popov “had so many opportunities to leave, to walk away.”

“He chose not to,” she said. “He used deadly physical force against O’Shae for no justifiable reason.”

The trial comes nearly three years after Sibley’s killing rattled New York City’s Black and queer communities. Following Sibley’s death, fellow dancers gathered at the gas station on Coney Island Avenue to vogue in his honor and call for justice.

In the year Sibley was killed, New York City recorded the most hate crimes against gay men and Black people in New York City since at least 2019, with 116 and 56 reported incidents, respectively, according to NYPD data.

At least 11 hate crimes against LGBT people and 10 against Black people were reported in the first three months of this year, according to the most recent police data.