The eye-rolling theory behind Kendall Jenner not celebrating sister Kylie giving birth.

We must remember that in our age of Instagram, what you say is often overshadowed by what you don’t say.

Case in point: Kendall Jenner being the only Kardashian not to have congratulated Kylie on the birth of her daughter Stormi.

Sound the alarms, we know…

But, in the interest of Kardashian drama, we’ve deep-dived on this not at all important yet still interesting issue and apparently this one boils down to the fact the father of Kylie’s child, Travis Scott, and Kendall Jenner used to date.

Maybe.

LISTEN: As a family who have built their fame in the public eye, do the Kardashian’s have a right to ask for privacy? Post continues after audio.

Let’s review the ‘facts’…

So, as the rumours go, in 2015-2016 it was speculated that Kendall Jenner and Travis Scott had a brief fling.

She (Kendall) was at his ‘Rodeo’ recording party in December 2015, and then in 2016 he was at her 21st birthday party in November.

Then, Babe said that according to an article from OK! Magazine, Travis was once overheard bragging to friends that Kylie was “way better in bed” than Kendall.

“Kylie’s way better in bed than Kendall and has more to play with, but Kendall’s got more personality,” said an ‘insider.’

Hmmmmm.

However, that article is no longer available and re-directs to a ‘Travis Scott Kendall Jenner’ search on Radar Online – which is another publication owned by media company American Media, Inc – who also own OK!.

Now let's all also remember that Kendall wasn't at Kylie's birth, she had to get Skyped in and barely features in her birthing video. In fact, all she says is a cheery "hey" to the camera, followed by a wave.

Scorn, scandal and contempt we tell you!

So to summarise, the reason why Kendall has yet to publicly congratulate Kylie has everything to do with a pending sisterly meltdown over a rumoured ex-boyfriend and nothing to do with the model's busy work schedule and international travel.

Stay tuned, friends, stay tuned.