The actor joked that he was asked to fill in for Helen Mirren and Maggie Smith at the last minute, and didn't have time to find childcare.
"We had a soccer game, there was a neighbor's birthday party, a nut allergy, I didn't have time to do my hair," he explained, adding "It doesn't matter, it's great to be here."
He the warned his three young children: "Don't blow this for me."
Watch the act below: