"Good night with good people," he captioned the post.
The former Jonas Brothers member reposted the photo on Instagram Story, writing, "When you show up in the same outfit @deltagoodrem." Delta also took to Instagram Story to share the pic. Although Nick and Delta looked very comfortable with each other, many fans didn't want them to rekindle their romance.
At the time, Australian media reported that the songstress found Mitchell 'too blokey' and allegedly broke up with him over the phone.
The co-stars on "The Voice" sparked of dating rumors on the show in April 2017.
The "Innocent Eyes" hitmaker could be seen putting her arm on Nick's shoulder, while he rested his hand on her knee. Another wrote, "Can't they just be friends like has anyone thought of that? " The two first sparked reconciliation speculations after they were photographed hitting the gym together in Los Angeles last month.