Kristin Cavallari's Marine Date -- Mother Approved

Kristin Cavallari has one less thing to worry about when she hits up the Marine Corps Ball with Jonathan Burkett -- his mother is on board.

As TMZ first reported, Cavallari accepted Burkett's Twitter invitation to the event in San Diego in November. Burkett's mom tells TMZ she's not sure why her son chose KC, but she thinks it was a "cool" and "gutsy" thing to do.