Channing and Jenna were married for nine years.
The dance pro, who is famed for her role in the 2006 film Step Up, bared all about the shock news in her her new book Gracefully You: Finding Beauty And Balance In The Everyday.
‘There I was, on a plane, alone, finding out about his new relationship. I felt blindsided,’ she wrote.
The revelation came just moths after splitting from acting hunk Channing, with whom she shares her six-year-old daughter, Everly.
Jenna went on to add that her former hubby of nine years had given her no warning that information of his new romance was set to arise, describing the fact she found out at the same time as the rest of the world as ‘difficult’.
She continued to confess that she initially contemplating posting her feelings on the situation on social media, before admitting, ‘Instead of reacting the way I wanted…I asked myself this: How do I choose grace in this moment?‘
Earlier this year, Price Tag hit maker Jessie J dished some details on her and Channing’s relationship, but insisted she wasn’t going to say too much.
Speaking to The Times, she said, “Chan and I got photographed before our relationship was even a thing and that created such pressure.
“We’ve needed time to get to know each other. We’ve just had our first holiday together, which was wonderful, but that’s all I’m saying.”
Jessie previously bared all about why she and the Magic Mike star had been keen to keep things on the down low, telling The Sun’s Dan Wooton, “The reason we kept it a secret for as long as we could was because we wanted to really enjoy it without it being magnified into something that it wasn’t yet. You don’t go on a date with a guy twice for a dinner then fall in love – well maybe you can, but that’s not me. That’s not who I am. I need time.”