Bezos and Mackenzie divorced in 2019.

Jewett made this known via the official website of the 'Giving Pledge,' a philanthropic web page created by his wife.

"I am married to one of the most generous and kind people I know — and joining her in a commitment to pass on an enormous financial wealth to serve others," Jewett wrote. "I look forward to the growth and learning I have ahead as a part of this undertaking with MacKenzie," he said.

It would be recalled to Bezos and Mackenzie divorced in 2019 in what many described as one of the biggest settlements in history.

The divorce settlement made her among the richest people on Earth, currently holding a $53 billion fortune according to Forbes after receiving a quarter of Bezos' Amazon shares.

They were married for 25 years and have four children together.