Lisa Vanderpump says she doesn't understand why Lisa Rinna recently shared a nude selfie online. The 56-year-old weighed in Wednesday in an interview with People on her 53-year-old "The Real Housewives of Beverly Hills" co-star posting a naked photo on Instagram. "I just don't know why you'd want to," Vanderpump said. "I mean, sure she looks great. I mean, she's tiny and she's toned. But I think my kids, even if I looked that good -- which I don't -- would say, 'Oh mom, what the hell are you doing?'" Rinna made headlines for sharing a nude selfie Sunday following news Playboy will again feature naked women. The television personality and mom-of-two appeared on the cover of Playboy in 1998 and 2009. "It's back. I got scared then I said I'm 53 -- zero [expletive] given! Cheers to @playboy for going back to nudes," she captioned the photo. "The female body is so beautiful, every size and every age. Be proud! #thefemalebodyisbeautiful #allshapesandsizes #loveyourself #loveyourbody," the star added. Vanderpump and Rinna have co-starred on three seasons of "The Real Housewives of Beverly Hills," which airs Tuesdays at 9 p.m. ET on Bravo. Vanderpump also addressed in the People interview reports she will leave the show after Season 7. "Unless they fire me, no," she said of her rumored departure. "You know, every year we talk about it. Last year I kind of thought it was my last season because they were so mean, and then I came back and I've had a great season."