Katy Perry partied with Diplo in Las Vegas on Monday night (28.07.14).

The 'Dark Horse' hitmaker, who reportedly rekindled her romance with the DJ, real name Thomas Pentz, last month, was spotted enjoying a cosy dinner with him and 12 other pals at Andrea's restaurant inside Encore at the Wynn hotel to celebrate a friend's birthday.

A source told E! News that the couple ordered an assortment of sushi, ice cream and a flaming Mt. Fuji dessert before they headed to XS nightclub, where Diplo took over the DJ booth.

The singer, 29, and her pals sipped cocktails and danced the night away during his performance.

Katy, who split from John Mayer earlier this year, was first linked to the music producer at the Coachella Valley Music & Arts Festival in Indio, California in April.

They ended their fling a month later, but reunited for a holiday in Jamaica last month.

A source previously claimed that the duo called off their relationship because it was moving too quickly and Diplo, 35, wanted to introduce the 'Roar' singer to his family.

The insider said: ''Diplo broke up with her because she does not want to be in a serious relationship. She's doing OK and not too sad about it. They wanted different things.''