The couple grabbed coffees in Sydney this afternoon, and by nighttime, changed into fancy clothes to celebrate his The Voice.
Joel is a mentor on the Australian version of the show, along with Seal, Delta Goodrem, and Keith Urban.
Kim Kardashian will present an award that has yet to be announced. The Jealous singer looks to be expanding his acting career in addition to his already successful music endeavors.
His television show Kingdom, which is centered around MMA fighting, has wrapped it's third and final season.
On Sunday he will play host to Kim Kardashian, Nicki Minaj and even Michael Jackson's model daughter Paris.
On Delta's Instagram story, she captured the shocking image simply 'denim party,' while Nick shared the same image, writing: 'when you show up in the same outfit.'The singer and actor shared two more pictures from the party, which appeared to be a small gathering of close friends.
Nick and Delta appear to be at a mutual friend's party, and were witnessed perched on chairs in their double-denim ensembles.
The former Neighbours actress draped her arm around the hunky Jonas Brothers singer, flashing a peace sign.
Snapped outside a recording studio in Hollywood, the 32-year-old laughed off questions about a rekindled romance with the Chains singer.
Cutting a casual figure, The Voice Australia coach opted for dressed-down attire including flared blue jeans but still showed a hint of cleavage in a low-cut black tank top which was tucked into her pants.