Paris Hilton has to draw the BFF line somewhere.
The heiress - and Nicole Richie pal - says she won't change Harlow's diapers.
"Nicole is, like, the best mother. She's so hands on, so she does that," Hilton says on the Oct. 13 episode of The Tyra Banks show (check local listings). "I’ve never changed anyone’s diapers."
Hilton says she and beau Benji Madden have some time before they have a baby of their own.
For now, they like to spice things up. "Sometimes," she tells Banks, they take baths together.
"If we take a bath together, he’ll wash my hair," Hilton says. "We’re very close."
She says Madden first asked her out at Richie's mom's house.
"That was our date, and we played with Harlow, played music in the studio, and then we ended up going to see a movie and then from there..." says Hilton, who calls Madden "baby love."
Hilton also talks about her "baby voice," which she says she speaks in "when I get shy ... I've been doing it since I was a teenager, and I’m kinda trying to grow out of it now."
As for her new MTV reality show, Hilton says, "I just thought I would have a lot of fun to meet people who are not from Hollywood, not all jaded...."
More than 30,000 tried out for the show and "some had to pass a psych test - and some of them didn't," she says.
So what does Hilton look for in a BFF?
"Someone I can trust," she says. "I've been hurt in the past. I just want someone who's not using me. Someone who really wants to be my friend for the right reason."