Why James Packer is expected to miss longtime friend Karl Stefanovic's wedding

James Packer will reportedly not be in attendance as longtime friend Karl Stefanovic marries Jasmine Yarbrough this weekend.

The Daily Telegraph reported that the Australian billionaire, 51, will miss this weekend's joyus festivities in Cabo San Lucas, Mexico, to instead be with his mother Ros. He was said to have changed his plans after she flew to Argentina to meet him and celebrate her 80th birthday in South America.

"Unfortunately he is not able to make the wedding due to this being such a special opportunity to spend time with his mother on this auspicious birthday for her," a source told the publication.

The TODAY host, 44, and the fashion designer, 34, are set to wed Saturday at the exclusive Palmilla One&Only resort.

WATCH: Pete Stefanovic congratulates brother Karl on engagement (Post continues.)

But, according to the source, Packer, a former head of Nine, and Stefanovic's bond remains strong.

"While he's disappointed he'll miss it, James is looking forward to catching up with Karl and Jasmine after the wedding and celebrating with them at a later date," the source added. "There is nothing but love between James and Karl."