oh duck

i was driving the children to sunday night ramp up and miss lisa was tagging along (she was early for bible study at our house so she rode with me to take the children up to church).  we were talking about summer plans when this dialogue happened:

miss lisa: oh... duck. (m2 lowered her head).
m2: why did you say to duck?
miss lisa: well, pumpkin there is a duck crossing the road in front of your mother's car and i was just pointing him out.
m2: oh.

i don't know why but this cracked me up.