My own personal drill sergeant

I took up running a while ago (that's a whole other post in itself) and a nice by-product recently has been that my two sons (First Born aged 9 and Second Born aged 7) like to come out running with me now and again. Separately - never together. I couldn't run with both of them for fear of them jostling each other into a bush or an oncoming bus. They are capable of arguing about who gets to spit first when they brush their teeth - arguments about who gets the pavement are entirely likely.
When I first started running with Second Born (he was 6 then) I was careful to run to accommodate him. I incorporated plenty of walking breaks and made sure I didn't go too fast. After all, he only has little legs, right? So after a while, I signed up to run the Race for Life with some friends. SB was cross when I told him because he couldn't run it too, being (a) too young and (b) the wrong gender. So I promised him faithfully that I would find a race we could enter and run together.
As luck would have it, I found the perfect thing: a 2.5km race taking place 1 week after the RFL, minimum age 8 but under 8s can run with an adult and what's more, it was being held only 5 minutes away from my parents' house where we were going to be visiting anyway. Perfect! So I gleefully told SB about it expecting an enthusiastic response. He didn't say anything. Now, he can be shy so I thought maybe he was having second thoughts. I told him he didn't have to do it if he didn't want to, but if he wanted to run, I would enter us. He still seemed unsure. This is the conversation that followed:
ME: You don't have to. But if you want to enter, I will run with you. What do you think?
HIM: We-ell......
ME: Yes? What?
HIM: If I run it, do I have to stay with you or can I run ahead?
ME: (!!!!!) What, do you mean you think you can beat me?
HIM: Well, I don't want to run it if I have to go too slowly.......
ME: (Laughing now) Listen, kiddo, if you reckon you can beat me over 2.5km, you go for it. Just meet me at the finish line!
HIM: OK, I'll do it.

And of course, he whupped me. By a minute and a half. As I came panting down to the finish line, he had already finished. And collected his medal. And his goody bag. And he was chatting to his granny and downing the free orange juice.
Fast forward a couple of months. We went out on Sunday morning for a nice gentle run - half an hour, 3km or so, nothing strenuous. Towards the end of the route there is a wee hill - not big or long but quite steep. I said something to the effect that as long as we took it gently and steadily, the hill would not be a problem. SB's response? "Come on Mummy, ATTACK THAT HILL!" and off he charged.
I have created a monster.