Leave it to an ex to fan the competitive fires among the Kardashian-Jenner sibs. Kendall Jenner appeared on “The Late,Late Show” this week where one of her “Spill Your Guts or Fill Your Guts” demands was to rank her siblings’ parenting skills for James Corden’s guest host — and Kendall’s former beau — Harry Styles. “I’d say that Rob is No. 1. He’s so good to his daughter!” she gushed, according to People. “They actually all are amazing. They really are. Like, can’t make it up! They are, I swear!” she assured the audience. Despite that claim, she opted not to drink 1,000-year-old egg nog and went ahead and ranked her sisters’ mom capacities. “It would be like, Khloé, Kim, Kylie, Kourtney,” she admitted, laughing and turning red. “They’re all amazing!” she added.