Diddy‘s ex-girlfriend says she watched an unnamed woman have sex in front of a party full of people in Las Vegas … all while an unidentified rap icon flirted with her.

“Jane” was back on the stand for another day of testimony Thursday … and, she answered questions about a January 2024 trip to Sin City to hang with the unnamed rapper — described by her as a legend and icon in the industry — and his wife or girlfriend at a birthday party.

Jane says she flew on the rapper’s private plane — Diddy was unaware because they were on a break at the time, she adds — and met up with a group of people when they touched down, including Antoine … who she says was a male escort who knew the rapper and his wife or girlfriend.