If you are inclined to ask my kids something involving Santa, just be prepared for the answer.
Our family has made a choice not to involve Santa in our celebration. Rather, we center our holiday on the birth of our Savior, Jesus Christ. We want our kids to understand the true meaning behind Christmas which is a Savior who humbled himself to be born in the form of a man, live a sinless life, and die on the cross for the forgiveness of MY sin.
"Do not be afraid. I bring you good news of great joy that will be for all the people. Today in the town of David a Savior has been born to you; he is Christ the Lord."
Luke 2:10-11
So, my kids will tell you that we have chosen not to believe in Santa. We are focused on our Savior.