The Older Son, the Younger Son, and the Critical Mom

"Why did you fart?"
The son  to whom my eldest had put the question had retired, hermit-like, to his room, and was pleased to be presented there with some cupcakes.
"I'm was just asking him a question, Mommy.  That's all!"  The elder had said to the younger, who had favored him with a fishy stare.
"Hey, please don't put your toe on the table.  That's not polite," says my husband to our oldest son, who, with four guests sitting around the table for a traditional coffee-and-cake, had introduced his toe into the conversation.  There it peeked over the edge of the tablecloth as if it, too, wanted some cake, while the teenager lounged with that inimitable air of "I'm gonna get away with this because you're not gonna stop me in front of other people."
"Besides," the older son added, gesturing to me, "She isn't polite either, right?"  There's nothing like distraction to derail the parents.  Why wasn't I polite?  Because I had asked if he would play Tequila on the clarinet for our guests,  when I was supposed to know perfectly well that he doesn't like to play in front of guests and by the way I shouldn't be pushing his sister (who was about to execute a Marcello piece on her violin with considerable charm) when she didn't want to play either.
  How well I remember the younger son, age three, getting even with our eldest.  The eldest had teased him and then gone upstairs to read.  And if you hadn't known that he'd teased the youngest, you'd think the youngest a completely psychotic devil.  Here's what happened.  By chance I was going up the stairs right behind the three-year-old, who, unbeknownst to me, had plans.  And we got to the top of the stairs and lo and behold, instead of heading into his own room, he went down the hall to his brother's room.  Hmmm, thought I, following him.  He was in fact so intent on his brother that he didn't notice that I was right behind him.  He walked right into the eldest's room and here, though I did not see it, I can imagine the gloating look on the youngest's face.  There sat his eldest brother, deep in a book, quietly facing the window, oblivious to the small person right behind his chair and the mother standing in the doorway.
Up went the small person's fist.  Before I could even open my mouth to yell, "Stop," down came that little fist, right between the shoulder blades.  WHAM!!  The results must have been most satisfying to the younger brother.   I could tell it hurt a lot and ran to the eldest to see if any real damange had been done, but apart from having the wind knocked out of him and a bruise that would fade in a day and considerable scraping of his dignity, he was fine.  I proceeded to the room of the younger son, who was whistling a happy tune.  He greeted me with a look of alarm.  "You know, Mommy, it's the funniest thing," he invented.  "I, like, came up the stairs, and somehow accidentally I went into, uh, you know, his room.  And then like by accident my arm just happened to swing around and by accident it landed on him."  He smiled.  By the end of the explanation he believed everything he'd said.
Well, now that he's twelve and the other one is fifteen, I can leave the house without worrying that the two of them will kill each other.  They'll play video games together about people killing each other instead.