George Koh is alleged to have murdered rising star Harry Uzoka after stabbing him in the heart outside his home in Shepherd’s Bush, west London, on 11 January.
Mr Uzoka, 25, called Koh “a fake” on Instagram and arranged a fight after finding out he had claimed to have had sex his girlfriend, model Ruby Campbell, the Old Bailey was told.
The fight took place after French model Annecetta Lafon, who knew the two male models via social media, arrived in London at the end of December.
Giving evidence on Tuesday, she told jurors that both men followed her on Instagram and knew she was working in the capital because of her online posts.
Ms Lafon said she met Koh at the beginning of January when he arranged for a taxi from her hotel in Camden, north London.
She said they had drinks when she arrived, adding that “he told me that he liked me and he was harassing me”.
“He wanted sex with me and I didn’t want to,” she said.
Ms Lafon said Koh started talking about Mr Uzoka after around an hour and a half.
“He told me that I was pretty and obviously I have other boys who talk to me, then said, ‘oh, by the way, I saw that you know Harry’,” she said.
“He did ask me if I had already met him. I said, ‘no’.”
She said Koh claimed he had slept with Mr Uzoka’s girlfriend, Ruby Campbell.
Ms Lafon stayed with Mr Uzoka a few days later and said they got on “very well,” adding he was a “good friend”.
She told him what Koh said about his girlfriend, to which he reacted with laughter.
“He was not surprised at what he was saying because it wasn’t the first time it had happened,” she said.
“He showed me messages on Instagram saying he (Koh) was a big fan and saying that he admires him.”
A feud between the male models escalated in a series of “angry” phone calls and messages on social media.
Mr Uzoka then planned to meet up with Koh and “fix him”.
He arrived for an arranged confrontation with his flatmate Adrian Harper, both armed with dumbbell bars, the court heard.
Koh, assisted by friends Merse Dikanda and Jonathan Okigbo, both 24, brought at least three knives to the scene, including a machete, prosecutor Richard Horwell QC said.
“It is not difficult to work out which side won. Uzoka and Harper were outnumbered and bars stand little chance against knives,” he told the jury on Monday.
Koh, who denies murder, handed himself in to police three days after the incident.
In a prepared statement, he said: “I acted in self-defence because I feared that he would kill me or cause me serious injury.
“I had no intention to stab him in the chest. I was on the floor when he fell onto me. I maintain that my actions were reasonable given the circumstances.”
The trial continues.