Disclaimer: Marvel's characters do not belong to me, much as I wish they did. This story be harmless fluff, and so say I, ar, ar...
Hank folded his hands behind him, assuming his sternest expression. "Robert, I am grievously disappointed. Grievously." He shook his head sadly. "I'm the first to advocate a little merriment, the odd small joke to brighten the day ... but this?"
"It was funny!"
Hank managed to smother a small chuckle. "Indeed, there were humorous aspects. But what you must realize is that it was also embarrassing, and yes, dangerous. So many things could have gone wrong!"
"Consider the unpredictable nature of our lives, Robert. What starts out as a simple prank could have dire consequences. Take today as an example-"
Hank continued, ignoring the interruption. "Today, a seemingly harmless prank could have turned into a disaster. Oh, you say, but there's no possible way that itching powder could be dangerous-"
"You could get a rash..."
"Well, yes, there is that. But not SERIOUS danger." Hank waved an admonitory finger. "But today we were in a battle. And while it is amusing for Cyclops to have his briefs anointed with sweat-activated itching-powder ... which was very ingenious by the way..."
"You're welcome. Anyway, while it IS amusing, mid-battle with the Villain Of The Month is perhaps not the best time for it to take effect."
The object of his lecture hung his head guiltily. "I know."
"He could have been stepped on. The Juggernaut is very heavy, you know."
"It's a good thing for us he thought it was funny."
Hank relaxed a little. "I know you are. And as long as you promise not to do it again, we'll say no more about it, all right?"
Robbie nodded solemnly. "Yes, Daddy."
Hank picked his five-year-old son up, and sighed. "And next time Uncle Bobby suggests something ... let HIM do it. Please. For Daddy's poor old heart."