Paris Hilton feels like a grown-up, thanks to Benji

Thanks to her current boyfriend, musician Benji Madden, and their more low-key romance Paris Hilton says, "I just feel like a grown-up now."

This heiress-turned-actress was at San Diego's Comic-Con International in support of her new, well-received film, Repo! The Genetic Opera, when she spoke with People about her less, media-frenzied life. She said that Madden has been teaching her to take on more responsibility.

The couple's been writing and recording some songs together. "We just wrote together," Hilton said. "I had a whole recording studio in my house and so we've been working there every night. We wrote together on two songs for my Best Friends show."

"He helps me because he's an incredible writer and we're on the same wavelength and so we're working well together as a team," she said. "Benji will bring us beats and then we literally just sit there and write to the beats about what I want to talk about. The music is really fun. It's really just happy and fun dance music."

They've also been spending some time with the other Madden clan, as in Joel Madden, Nicole Richie, and their daughter, Harlow. Hilton said they've been babysitting every once in a while.

"We just saw her like a week ago. She had her six-month birthday. I can't believe it. She's getting so big and is so cute. She's laughing now and trying to call, which is so sweet. I love babies!"

Does this mean that Benji and Paris will be following the footsteps of their dear friends soon?

"I don't know," she mused. "We're so in love and so happy right now and it's only been like six months. So we'll see what happens, but we're so in love and so happy and things have never been better. I finally have a nice guy."

"I think my whole life I was kind of living as a teenager and not really taking responsibility," Hilton told People. "Now I realize that I'm an adult and I'm running a huge company and I'm in love. I'm in a great relationship. I have my family. I'm just excited for life."