Reality star Kourtney Kardashian and her longtime boyfriend Scott Disick welcomed a bouncing baby boy on Monday, Dec. 14, a rep confirms exclusively to Life & Style. Mason Dash Disick was born in L.A. and weighs seven pounds, six ounces and 19½ inches long. This is the first child for the couple, who both star on E!'s 'Keeping Up with the Kardashians.'