I Made A Boy Cry Today

I was at the Superstore, trying to find corn chowder in the soup aisle.  In the middle of the aisle was a mother, a probably 11 year old boy, and two younger sisters.  The mother was exasperated.  When I came upon the scene, the boy was holding a cellphone out, baiting the mother.  She was obviously fed up, and asking the boy to give her the phone.
"What are you gonna do?  Gonna phone Dad?  No you're not!", the boy taunted, not giving up the phone.  He kept saying this whole bit over and over again, each time more and more petulant.  The mother tried her best to keep her patience, but was on the verge of a blowup.
This cellphone fish-and-bait went on for about a minute.  I remember thinking how this kid is just 10 years old or so and already pretty much in control of his mother.  That made me mad at him.  Also mad at her, as I really wanted her to declare her parental power over him.  Then I started daydreaming about how this woman likely has very little power in her household and suffers her lot in life.
I'm not sure how the cellphone incident was resolved because I turned my attention to corn chowder.  Before I could choose any, though, the boy started running around their cart, punching the back of one of the girls, knocking groceries in the cart all over the place.  The girl starts crying, the mother yells at him ineffectually, and he swears at her and calls her demeaning words.  The mother is thisclose to freaking out and crying, but focuses all those emotions into reorganizing the grocery cart and stating the usual "wait 'til your father gets here" and "this is the last time I take you grocery shopping" desperate lies.
There's the family:  Mom fuming into her groceries, older daughter crying, younger daughter helpless, and little tough-guy kid strutting around like the king of the world.
There's nobody else in the aisle but us.  They're still in the middle of the aisle and I'm near the end of the aisle, as he begins to expand his domain of power.  He walks up towards where I am.
"Hey, kid," I say, using my stern adult father voice. "Don't be an asshole.  Treat your mother with some respect.  She doesn't deserve to be treated that way."
At this moment this thought ran through my head:  "how do I know what kind of a mom she is, maybe she does deserve this heap of abuse" but I was pretty sure she was the victim here.
The kid looks at me and I can tell he's a bit shaken by being talked to by a stranger.  He retreats to the safety of his domain, around his family.  As he's walking back though, in reply to my "she doesn't deserve to be treated that way" he says "Yes she does.  She's an {expletive I couldn't quite make out}.
Back in his power-zone, he looks back at me.  The mother, I can tell, has heard our little exchange, but I can't tell if she's appreciative of my effort or not.  She's pretty tight-faced at this point.  He's looking at me, and I give him a ridiculous evil-eye stare.  A really long, intense evil-eye stare.  A threatening, really long, intense evil-eye stare.  I imagine I looked like I was ready to rumble with him.
It's affecting him, I can tell.  I can practically see the tough-guy fizzle out of his demeanor.
To reclaim his power over his family, he tries to sit in the cart, but his mother tells him not to.  He then tries to pull the cart past me, even though his mother is still trying to sort the groceries he knocked over earlier.  As he passes me, he lets go of the cart.
I quietly yell (yes, it's possible) "HEY! Smarten the fuck up, kid.  Asshole kids grow up to be asshole men.  And nobody likes asshole men."
By the time I finish my sentence, he's walked past me, out of the aisle.  After vacantly looking at the chowders, I walk my cart out a moment later and see him leaning against the end of the aisle.  He's silently crying.

I made a boy cry. I didn't know how to feel.  Even though he was a total hellian asshole kid, I didn't know how to feel.

And, I didn't get any corn chowder.