Potty Training a Boy: AKA "Adventures in Hilarity"

So we've started really focusing on potty-training Ethan, who will be 3 in about a month-and-a-half.  For the past few months we've been laying the ground work:  talking about the poo and the pee a lot; making him tell us everytime he poo's or pee's in his diaper; and telling him that, even though he was allowed to poo and pee in his diaper, he is only allowed to do so IN the bathroom, because that is the ONLY room any of us poo or pee in.  He's been very willing, surprisingly enough, and we often see him make a beeline for the bathroom, hear him do some grunting, and then return to the living room to say to all of us "I pee'd.  Change me."  

By golly, I think he's ready.

So tonight he was in "big-boy underwears" for a while.  Spiderman ones.  At one point in the evening, Marty looked Ethan in the eye and said: 

"You better not pee on Spiderman.  He'll get mad and fling his spidey-webs at you.  (cue re-enactment of Spidey flinging webs from his wrists, complete with detailed sound-effects.)

And I tell you what...I haven't seen Ethan freaked out by a comment like that in a good while.  He stared at Marty for a while, then down at the Spiderman graphic on his crotch, then back up at Marty.  

"I-I-I-I not pee on Spiderman.  I not.  I no want his webs." 

He then looks down and addresses his crotch..."No Pee...no webs."