The Voice started its Battle Round on Monday by revealing that Adam Levine and his team mentor Charlie Puth were 'best buds'.
The 40-year-old Maroon 5 frontman leaned on Charlie, 27, to help prepare his artists for a dueling duet and called him the 'perfect adviser'.
'We know each other. We're friends. We work out,' Charlie said.
Good friends: Adam Levine and Charlie Puth revealed they were 'best buds' on Monday's episode of The Voice as the Battle Round started on the NBC singing competition show
Adam meanwhile gushed about his pal.
'He's got a vast, incredible knowledge of music, and he has the ability to see the music in ways that most people can't do, and so he's the perfect adviser,' Adam said.
Charlie shared that he sleeps over 'a lot' at Adam's house and said they often talk about music.
'I wanted to be an adviser, and I was really excited when Adam asked me because this is what I do. This is my living. I'm a record producer. I try and get the most out of an artist, including myself,' Charlie said.
Record producer: The 27-year-old record producer said that he and Adam are friends and 'work out' together
The See You Again singer also recounted how they met and became buddies.
Charlie said he was driving on Pacific Coast Highway when he saw Adam in a friend's car.
'And I rolled down my window and I said, ''Where are you going for lunch?'',' Charlie said.
Road meeting: Adam was driving on Pacific Coast Highway with a friend when Charlie spotted him and asked where he was going for lunch
Adam interjected that they stopped and had lunch together.
'We became best buds ever since,' said Charlie who previously was an adviser on season 11 of The Voice in 2016 for Alicia Keys.
Charlie helped Adam's singers Domenic Haynes and Trey Rose for their Battle Round performance to I Need A Dollar by Aloe Blacc.
Battle round: Trey Rose and Domenic Haynes were pitted against each other by Adam
Adam wanted to change the arrangement to distinguish their voices and Charlie ran with the idea.
'Do like a little bass thing and a shaker thing,' Charlie said as he planned out a 'musical rollercoaster' to separate their voices.
Domenic and Trey took the suggestions by Adam and Charlie to heart as they battled it out.
Tough call: The singers took the advice from Adam and Charlie to heart and it showed during their duet
'I'm just really proud of the both of you, and I thought it was a great performance. So, this is tough,' Adam said afteward.
Adam picked Domenic as the winner of the battle.
'Trey was great. Domenic is indispensable. It's, like, I can't not have Domenic on my team,' Adam said.
Moving forward: Domenic was named the winner of the Battle Round and stayed on Adam's team
The coaches: Blake Shelton, Kelly Clarkson, John Legend and Adam are the coaches for season 16 of The Voice
New coach John Legend, 40, agreed with his decision.
'You gotta keep him because he's a star,' John said.
John enlisted Khalid to help his team as a Battle Round advisor while Kelly Clarkson worked with Kelsea Ballerini and Blake Shelton brought on Brooks & Dunn.
Team adviser: Khalid was enlisted as the team adviser for John's team
Each coach after the Battle Round must decide which singer remains on their team, while the others coaches have the option of stealing losing singers.
John decided to have Matthew Johnson and Shawn Sounds compete against each other.
Matthew and Shawn were delighted to receive advice from John and Khalid as they prepared to sing Never Too Much by
