ha ha pjaz....same story here, we once needed to pop up to the village shop for some carrots and my 5 year old said he would run with me rather than take his bike....100m later (like you said) he stopped running and walked the rest of the way......
he then told the boss/wife/mum etc that he stopped running to wait for me.......as i was so slow......
last weekend we went to the coventry half marathon (up north!!),,,,and he had great delight when we got home showing me some pictures on his camera and a video (santa bought him a cheap camera last year)
the video "oh i took a video daddy,,,," oh thats great am where am i?
"oh theses are all the people in front of you...."
my wife was wetting herself laughing,,,,and even i had to laugh.....
oh well a 1:37 pb wasn't good enough.....opps a bit off thread,,,,i was using my garmin 101 at the time...