OK Magazine reports that Nicole Richie’s post-birthing slimming secret is the Spanx undergarments she’s been wearing. (You know, the hose replacement profiled on Oprah?) But I maintain that the real secret is the mad partying that she and baby-daddy Joel Madden have been doing. I mean, who the hell has a baby and then goes out and parties all hours of the night shortly afterwards? Doesn’t Nicole feel any maternal instinct? And she was doing so well, gifting other mothers, holding showers, participating in a charity that she and Joel had started.