Beyoncé and Jennifer Lopez, with their flat stomachs and bootylicious bottoms, wear them. So do Carrie Underwood, Halle Berry and Heidi Klum. Yummie Tummies, a hybrid between lingerie and ready-to-wear, are the newest big things you didn’t hear of. That’s because Yummie Tummies are foundation garments, a product women only whisper about – [...]