Katy Perry Crashed Prom With Ruby Rose on Night of Alleged Incident, on Video

For Katy Perry, the day that Ruby Rose says ended in an alleged sexual assault started the complete opposite — light, loud, and carefree — and TMZ’s got a pic and a video from that very night 16 years ago.

Check it out … Katy was all smiles on August 15, 2010, crashing a high school prom at Melbourne’s Grand Hyatt, where she grabbed a mic and belted out a few songs, including Beyoncé‘s “Single Ladies.” Ruby was with her at the time, though she’s nowhere to be seen in the shots.

From there, the pair later hit Melbourne nightclub Spice Market — the same spot Ruby claims things took a dark turn. Since the “Orange Is the New Black” star came forward with these allegations … a police probe has been sparked in Australia.

ICYMI, Ruby went public on Threads recently, accusing Katy of sexually assaulting her that night, claiming she had “rubbed her disgusting vagina on my face.” Ruby has since said she can’t speak further of the case after filing a police report against Katy.