Well, that wasn't very nice.
In a clip for the upcoming new episode of Keeping Up With the Kardashians, we see Kendall Jenner grow furious to learn that Rob Kardashian re-gifted her Christmas present for his new girlfriend — and while they don't say her name, we can only assume they mean his now-fiancée Blac Chyna.
RELATED: Are Rob Kardashian and Blac Chyna Having a Baby?
(Photo Credit: Getty Images)
"I gave that to him for Christmas! Yes, a keyboard, a pen and an iPad," the 20-year-old model said after seeing a picture on the girlfriend's social media account.
Kendall then explained in a confessional, "Rob is dating someone who's had a bad history with my family."
RELATED: Find Out Who Kendall Jenner is Dating Now
"It's so annoying to find out on social media, because his girlfriend posted it. There's some things that just aren't cool and I don’t think this is very cool," she said.
Catch Keeping Up With the Kardashians on Sunday at 9 p.m. on E! and watch Kendall and Rob's fight below: