She’s happy with boyfriend Benji Madden, but Paris Hilton is looking for a new best friend.

Slated to start shooting in May, the heiress, 27, has paired up with MTV to search for a sidekick on a reality show tentatively called Paris Hilton’s My New BFF.

So, what does her current BFF, Nicole Richie, think? “Nicole is my best friend and my sister, so she understands — she’s at home with her baby,” Hilton told PEOPLE at the Hollywood Hills party to announce the series.

While Hilton contends “there’s nothing that’s really hard” about being her best friend, she’s going to take the decision very seriously. “I going to be in my element in Los Angeles and really showing these women my life, which is completely different than The Simple Life.”

Contestants will live in a house with Hilton and she will teach them how to be her best friend, leading them through competitions of loyalty, endurance and “girl politics,” eliminating them one by one.

As for what she’s looking to get out of the 20 contestants, she says, “Someone that I just trust and not someone who’s going to stab me in the back — it’s happened a lot in this town. Just someone I can have fun with, someone who could be like my sister.”

Aspiring contestants apply over the phone or on the Web site www.parisbff.com.

PEOPLE