Lighting up his cigarette, Jack was all smiles as he took some time out to spend with his friends in Sydney’s Surry Hills.
One onlooker was surprised by the habit - which is far cry from the wholesome image he once projected as a child singing sensation that ultimately saw him win Australia's Got Talent over 8 years ago.
"Jack couldn’t seem to stop sucking on that cigarette," the bystander told New Idea.
"It really is a disgusting habit and it’s a shame to see such a young guy doing that to himself."
Watch Jack wow in his big Voice debut - article continues.
Speaking out about returning back onto our screens, Jack joked to New Idea that he hoped to turn more than just the judges' chairs.
“Hopefully I’ll find a husband,” he laughed.
“No, I’m happy and single. I’m just so grateful for this opportunity and to be let back into people’s lounge rooms and share my story.”