why kristin cavallari and jay cutler are getting divorced

Why are Kristin Cavallari and Jay Cutler getting divorced?Is it true one of them cheated?
Well,some quick background before the real thing.The in couple got married in Nashville in 2013.They were engaged twice before finally walking down the aisle.They have 3 children,two boys.Camden who is 7,Jaxon is 5 and a daughter Saylor who is 4.Such lovely names too,i especially
love Jaxon.
They filed for divorce on the 24th of April,with both parties releasing statements that there was no one else involved.

But is there more to it?Here goes....In previous interviews,Kristin had expressed how marriage was tough and that fact sucks.She also spoke about how they were great one moment and the next down in dumps.So really,for those who follow their trials,this is not so much of a shock.
But rumours are all over the net that she cheated and that is why they are getting divorced.
If you are familiar with their story,you will also remember During season 3, Kristin revealed that she had a strained relationship with her best friend, Kelly Henderson, after cheating rumours swirled between her and Jay.But her husband and former NFL player denied this,his wife also said she never believed it,but was all the same angry with her friend because of the way she went about it