The couple, who is all set to tie the knot, raise six children together, Maddox, 11, Pax, 9, Zahara, 7, Shiloh, 6, and four-year-old twins Knox and Vivienne, reported Sun online.
"Does it ache? Sure. The knees have gone, the back is crunchy. Getting the kids ready for school is every bit as painful as anything I had to do in this film," he said.
The 48-year-old actor also confirmed he and partner Jolie, 37, will wed, although there is much to plan.