Kendall Jenner wouldn't allow her partners to appear on Keeping Up with the Kardashians until they'd been together for "at least a year".
The 25-year-old model never involved any of her boyfriends on the E! reality series, which came to an end last week, and now one of the show's executive producers has revealed why fans never got to see Kendall's romances unfold on TV.
"Kendall's always had this rule - she felt like she had to be with someone for at least a year before she let them be a part of the show, because she doesn't always know what people's intentions are," Farnaz Farjam said on Bravo TV's The Daily Dish podcast. "So that's why we kind of kept her personal life out of it, just because she had a rule."
Kendall's younger sister Kylie Jenner, 23, also took a step back from the show in recent years, and although her romance with her ex-boyfriend Tyga was shown on the series, her ex Travis Scott - with whom she has three-year-old daughter Stormi - "didn't really want to participate".
Farnaz added: "I feel like Kylie became more participatory this last season towards the end, and Kendall has dipped in and out. But they were at an age... like, if you think about when you're a young adult coming into adulthood, I think you sometimes care a lot more what the outside world has to say about you.
"(Kylie) did share her relationship with Tyga. We showed their relationship quite a bit on Keeping Up, and then Travis (Scott) didn't really want to participate."
Although none of Kendall's romances made it to the E! show, she came close to reaching the milestone with her current boyfriend Devin Booker, as the couple celebrated its one-year anniversary over the weekend.
Marking the special occasion on social media, Kendall shared sweet photos of herself with Devin, 24, including one which showed them snuggling up together as they played with a dog, and another which saw them cuddle together whilst on what appeared to be a private plane.