How old are you, Mom?

I am watching 3 girls so their mom can go to night school 2 nights a week and one night while they were here McKenzie came bursting through the glass door, kinda like Kramer, and asks me, "How old are you mom?" I was a little surprised, and he was a little out of breath. I cautiously asked him why he wanted to know that and he said, "Christine says her mom is 40 and I want to know if you are bigger than her." I said I was 34 and he turned back outside and said, " Your mom is 40, Christine? Your mom is bigger than my mom." Yeay, I am not the bigger one!!!