Scroll two DIVs different height with a parallax-like effect

I’ve been scanning the web for a simple solution possibly without using a 3rd party library.

I have a Section with two DIVs that are placed side-by-side that have different heights. WhatI want to achieve is as I scroll down the web page, when I reach this Section the DIV on the left remains fixed until the right-hand-side DIV reaches the bottom and then the whole page continues scrolling down similar to some Parallax effects.

I like the Section’s height to be limited to 100vh and the solution should work on different devices except Cellphone.

I found ScrollMagic but it looks like you should know the heights before hand and in my case the DIV on the right has content that can change over time.

Any help is greatly appreciated.