Why Not The Parking Lot??

This morning as the kids and I were leaving Winco, Isaac declares he needs to go to the bathroom. Having a cart full of groceries and the other two kids and not really knowing what else to do, I told him we'd go to the car, unload the groceries than go back in. He starts screaming/crying, "I have to go so bad, so bad..." We hurry to the car and I start to unload the groceries, the whole time he's carrying on. I get all the groceries out and go to grab Lorelai when I feel something warm on my leg and hear Isaac say, "I'm sorry, I didn't mean to pee on you!" You guessed it! That little boy had dropped his drawers and was peeing in the Winco parking lot....ugh. I quickly look around to see if anyone had seen, an older gentleman may have, I tell Isaac to pull up his pants (!) and to stand by the car; then, when I'm sure he's not looking, I laugh...what else could I do...I guess in his mind, if he can pee in the backyard, why not the parking lot??