The singer was spotted supporting producer-DJ Diplo at 1Oak in NYC, where the DJ spun a surprise set, and the twosome sparked rumors once again that a romance is brewing between the pair.
While Diplo performed, the 29-year-old beauty partied with pal Rihanna. The duo was seen posing for pics with producer Walshy Fire, who was celebrating his birthday at the hotspot. Rihanna left her bra behind once again, wearing a white top and jeans, while Katy wore a black cone bra crop top and a black wig, covering up her "slime green" bob hair cut.
"Rihanna and Katy were dancing together, both drinking, having a great time, they both went into the DJ booth and danced there too," a source tells E! News of the famous friends.
The trio raged on into the wee hours of Saturday morning, partying at a table with 15 bottles of bubbly and Perry was even seen spraying her pals with a bottle of Cristal, according to Page 6.
Diplo reportedly spun until 3:30 a.m. and the crowd—including Katy and Rihanna—loved his set. The group kept the party going until after 5 a.m., making the most of their epic night.
The outing comes on the heels of Perry and Diplo cozy dinner date in NYC.
The musical duo ate at a restaurant inside the Marlton Hotel and then left together for the Amazing Spider-Man 2 premiere afterparty at the Skylight at Moynihan Station in Manhattan. We're told that they spent about an hour at the party and then headed to the Up & Down nightclub in the West Village.
Perry and Diplo (born Thomas Wesley Pentz) stayed there until about 2 a.m., after which they left separately but headed toward the same hotel.
Prior to their intimate dinner, the two were spotted getting flirty at the Coachella Valley Music Festival, igniting rumors that something more is brewing between the longtime pals.
An insider told E! News last week that, despite the pair's flirty behavior at Coachella, they were just "good friends," but another source seems to think that the two have been quietly more than that for a while.
"They get on really well," the source said. "He's just a fun guy and he makes her happy. They met when they started talking about doing music together, but there was an obvious chemistry there."
—Reporting by Sara Kitnick