A few internet tabloids have started talking about the Kim Kardashian and Kendall Jenner feud. And while the rumor sounds pretty serious, reports suggest that the reason behind the fight is pretty shallow.

How shallow? "Fifty Shades of Grey" shallow.

Reports claim that Kim K. had a private screening of the raunchy novel-to-movie flick with her friends, but she forgot -intentionally or unintentionally- to give younger sis Kendall an invite.

Kim tweeted, "Girls night watching a private screening of Fifty Shades of Grey!!!!!! OMG it's sooooo good!!!!!"

Kendall then replied, "and no invite?"

The Kim Kardashian and Kendall Jenner feud reportedly started when Kim K. didn't bother to reply to her sister's question. Tabloids have begun speculating that maybe the two sisters have had a rocky relationship to begin with, and that things just got worse eventually. Others who would like to assume the best between the two, said that maybe Kim privately approached Kendall after her tweet.

However, Celeb Dirty Laundry offered a different perspective on the whole feud, citing jealousy and envy as the root cause.

"So why didn't the lovely Kendall get to tag along with Kim? Who knows - but it might have something to do with Kendall's rising star status. You know what happens when you get too much star power in one movie screening room. Kim Kardashian would be the first to say that she's not threatened by her lil sis's blossoming modeling career and other endeavors that are beginning to do some heavy lifting for the the Kardashian/Jenner brand - but you know, in the back of her mind, she's got her eye on Kendall and wondering when the day's going to come when her star outshines her own," the site noted.

What do you think of the rumored Kim Kardashian and Kendall Jenner feud? Sound off below!