Kelly Osbourne is no stranger to fame or rock 'n roll, but she was absolutely smitten when Madonna asked her to be the face of her Macy's line Material Girl. During a casting call in San Francisco to find the next new face of the brand, Refinery29 caught up with Miss Ozzy to talk about what it's like to have a superstar boss, her most embarrassing fashion moment and her family on the set of Fashion Police.

Check out highlights from the interview below.

The Material Girl line has a vintage feel to it does your style come from a similar place? Definitely. I think I take my style from all walks of life, and all generations and decades of life as well. I love mixing '50s with '80s and classic with punk. And i think thats what this line embodies. It allows you to rework the same pieces in different ways so people dont realize that youve worn it before. I mean, I wear the same thing all the time if Im at home, Im in sweatpants. I dont care. But when you go out, you want something thats versatile.

What excites you the most about being the face of Material Girl? To have Madonna ask you to be the face of her brand, thats the coolest thing ever. As a young girl who grew up idolizing her and thinking that she was the be-all and end-all of how women should be, being the face of Material Girl is the greatest honor Ive ever had.

You're a member of the Fashion Police, but whats the worst fashion faux pas that you've personally committed? Sweat stains on clothes! Ill never be one of these girls who could walk into anything and say, 'I can do this!' I always get nervous. I always get scared. Im even nervous about judging these girls for this contest! You never want to disappoint, you never want to say that wrong thing. I get nervous and then I start sweating. People literally interview me on the red carpet and Im like dabbing my top lip, trying to be subtle about it. Im like oh my God, get me out!

So do you get nervous when you do a taping of Fashion Police? No, because Joan is just so funny! Were like a family now. Its mainly a comedy show based on fashion and it's one of those things where you have to have a sense of humor about yourself.

To read the entire interview, visit Refinery29.