How does one dress when making a comeback? Just take a look at Justin Bieber.

Though the 21-year-old pop star has had his fair share of fashion fails, he has recently stepped up his style game without abandoning his signature “skater boy” aesthetic. And he couldn’t have done it without the help of Karla Welch, the woman who has been dressing the Biebs for the past four years.

Recently, Harper’s Bazaar caught up with Welch to discuss her client’s approach to style—dishing on everything from his obsession with long tees to his favorite brands to which pieces he’ll never wear.

“He'll 'never say never,'” Welch told Harper’s Bazaar. “Musicians have more creative space, especially someone like Justin. He kind of does whatever he wants, which I love. There's a freedom.”

That care-free attitude, Welch said, is what ultimately led to his outfit choice for the American Music Awards this week. You remember? That killer oversized Nirvana tee by Fear of God. The choice was definitely polarizing, but Bieber pulled it off like a champ.

“He does not care if someone is upset that he wore a Nirvana T-shirt. He loved it, and he loves Jerry [Lorenzo], so it was about support,” Welch explained. “We knew it was the 20th anniversary of the Nirvana AMA's, when they won. He's a Nirvana fan. I'm a huge Nirvana fan. Like, ‘Let's wear the Nirvana T-shirt!’ … I think it's so funny that all these people are up in arms.”