Last fall, Caitlyn Jenner told Ellen DeGeneres that the former Olympian's grandchildren were nonplussed by her transition. "The kids get it. It's not even a big deal to them," Jenner said at the time. "They've been just great. They've never had any problem with it."While that may have been the case, that doesn't mean there wasn't some confusion along the way — particularly for Kourtney Kardashian's oldest son, Mason Disick, who turned 6 last December.On tonight's episode of Kocktails With Khloé, the host opens up about her nephew's struggle to understand what his grandparent was going through. "Mason was uncomfortable but [would] kind of, like, be distant to Caitlyn," she reveals.The younger kids were obviously less impacted by Caitlyn's transition. "They don't know the difference," Khloé says of nieces North West and Penelope, "which is the innocence of children. They know her as just Caitlyn."But Khloé also says that Caitlyn has done a wonderful job of allowing the kids to process the change, saying that Jenner "understood and handled it perfectly." Check out a sneak peek of tonight's episode, below.