Disick, 37, spent Saturday with ex Kourtney Kardashian and their kids, 5-year-old sons Reign and 10-year-old daughter Penelope Mason. Stepping out as a couple, Disick and the Keeping Up with the 41-year-old Kardashians star took their kids out for lunch at Nobu, Malibu, California.Late in April, Disick was seeking treatment at a treatment facility in Colorado. He checked himself out, however, and returned back to Los Angeles less than a week after arriving when on May 4 a video of himself was released from the inside of the treatment center.He has maintained a pretty low profile since then, although he has kept on spending time with Kardashian and their children. Recently they traveled together at Amangiri resort in Utah for a short vacation.