Holy hot mama! Less than six weeks after giving birth to her third child, a son named Reign Aston Disick, Kourtney Kardashian is flaunting her killer post-baby body on Instagram. The mother of three shared a photo of herself wearing a waist trimmer in her seriously glamorous closet–and she looks absolutely incredible. She captioned the selfie, “Gettin’ it right, gettin’ it tight…with my waist shaper!” Kourtney’s been keeping a relatively low profile since welcoming little Reign into the world shortly before the holidays, and was only recently spotted out at a family lunch in Los Angeles for the first time since giving birth.