There had been a bit of a rift between the pair years ago when she was fired at the audition stages after bringing her in on the judging panel of the "US XFactor" back in 2011. She only got to film episode before she was dropped which was very humiliating for her. Cheryl said her self-confidence dropped after her marriage split from footballer Ashley Cole and so she wasn't at her best.
However, Cheryl and Simon patched things up and she returned as a judge on the UK XFactor in 2014 and 2015. Remember she got hitched to Jean-Bernard and changed her name to Cheryl Fernandez-Versini? That marriage ended in 2016.
Cheryl knows Simon wants an "intimate wedding" so she was surprised to make the cut.