Father's Day

Here I am sitting at home writing this blog while my 9 year old son is setting next to me playing Call of Duty( World at war) on the Xbox 360 while my wife is out shopping. The game itself is a little violent (rated M because of the war like violence) but in a strange way I think it helps him understand the horrors of war. He made me 2 cards for this Father's day, One of them was just a regular one which was signed by all of his classmates at school (very cool), and the second was one were he substituted different adjectives for my name and title (dad). I thought it was pretty cool that he did this and of course I received one special coupon inside that card. The coupon read "for whatever you want me to do for you". he was very quick to note that it was "good for one time only". My only question is do I use it now selfishly to have him help me clean the garage or take out the trash or do I save it for when he is a teenager were it can have a lot more of a positive impact on his life? Hopefuly if I save it for 5 or 6 years, he wil still honor it because I do not see an expiration date on it.