Markle dated Vitiello three months before she started seeing the British royal and it's understood the Canadian chef grew tired of her diva antics.
Sources claim that she used to embarrass him by bragging to his friends that she was a successful actress in the American series Suits.
The final straw came when his friends praised the 38-year-old for inventing a new pasta dish Meghan falsely claimed that she had dreamed-up the recipe by herself.
The pair dated from 2014 until 2016 after her marriage to Trevor Engelson collapsed.
Markle fell for Vitiello after she and some cast members dined at his Toronto restaurant The Harbord Room and was smitten by the fact he was a celebrity too.
His mother Joanne Vitiello explained that soon stayed together at Meghan's rented townhouse that is located close to his restaurant and loved to stay in and cook for one another.
- 'Cruel': Thomas Markle Pleads With Estranged Daughter Meghan and Prince Harry to See His Grandchildren
- Doctors Can Tell: 27 Celebrity Nose Jobs Before and After — From Meghan Markle to Ariana Grande
- More Signs of Trouble? Meghan Markle Will 'Stay at Home With the Kids' After Being Removed From Invictus Schedule
Markle was invited to spend Christmas with his family in 2015 and she made a good impression on them.
"She had no airs or graces," explained his mother.
"She had a good sense of humor and was very personable – we enjoyed the conversations we had with her when we were with Meghan.
"They were serious as they were living together in the townhouse and they were in their thirties so they were not kids."
His mother claimed that she did not know the reason that they split but that Meghan stayed in touch via e-mail and told her she was dating somebody else too.
Although she never mentioned that the person was in fact Prince Harry.
Cory Vitiello has remained tight lipped about his relationship with Markle although he did say that she was 'a great girl' and that he was 'proud of her'.
We pay for juicy info! Do you have a story for RadarOnline.com? Email us at email@example.com, or call us at (866) ON-RADAR (667-2327) any time, day or night.