Miley Cyrus and Liam Hemsworth made their first red carpet appearance as a couple attending the Los Angeles Premiere of ‘The Last Song’ at the ArcLight Theatre in Hollywood on Thursday (March 25). At the event, Miley said her 10-year-old sister Noah is a big fan of Justin Bieber, while she’s feeling a bit too mature for his teen pop sounds. “Bieber fever … I’m not necessarily a fan. I don’t listen to that kind of music,” the 17-year-old told MTV. “I like Kurt Cobain. [He] is like my dream boyfriend. But my little sister was obsessed with him, and he actually gave her a shout-out on Twitter, and I thought that was really sweet. So I was like, ‘Thank you so much. That meant a lot too.’ … He called her a cutie, and I haven’t stopped hearing about it.” Watch the comments and what she had to say about being an ‘American Idol’ mentor below.