Hilary Duff Says ‘Mature’ Details a ‘Brief’ Relationship with Someone Older That Was ‘Not Illegal’ But Was ‘Inappropriate’

“If I wanted to reveal who inspired the song, I would,” Hilary Duff told Glamour in a cover story published Tuesday, Feb. 17.

Hilary Duff got candid about her single “Mature,” her first new original music in a decade. In a cover story with Glamour published on Tuesday, Feb. 17, the 38-year-old singer explained that the song reflects on a brief relationship she had with someone older. “It was not illegal, but inappropriate considering the circumstances,” she said.

She acknowledged the public curiosity surrounding the track, adding that while everyone speculates, the nuances of her past experiences are difficult to capture. She also pointed out that growing up in the industry from age 10 made it challenging to have relationships with peers her own age. “If I wanted to say who [the song was about], I would,” she teased.

Released in November 2025, “Mature” was co-written and produced by her husband Matthew Koma. The song marked her first original single since her 2015 album Breathe In. Breathe Out. In a statement, Duff described it as a dialogue between her present and younger selves, reflecting on past experiences with humor, gratitude, and self-compassion.

Following the release, fans speculated on the song’s inspiration, with many linking it to Leonardo DiCaprio because of the lyric referencing “very Leo of you with your Scorpio touch.” Koma further fueled the rumors by posting a meme of DiCaprio in Titanic alongside her album artwork on Instagram Stories.

Later that month, Duff addressed the speculation on On Air with Ryan Seacrest, saying she and Koma were amused by the rumors. “It’s 100% thrilling, and the internet is such a funny place,” she said. She added that nothing Koma posts should be taken seriously, joking that he’s “the biggest troll on the planet Earth” and enjoys leading fans down multiple rabbit holes for fun.