Because "next time" (TM) YSS will have to ask before he uses something that is not his. Sure.

Happened again. No asking. And again "next time" (TM) he will have to ask. Riiiiggghht. 

And while it's a little thing, there's a mountain of little things that this skid has never asked permission to do/touch/take. So, DH, yes, I'm pissed you just talked to him this morning and there are ZERO repercussions. THEN, when I'm obviously frustrated that it's the same-old-same-old, you tell me that part of it was that YSS had to apologize to me. Where was it? I came home at lunch and hung near the two of your for a good half hour and no one brought it up. An apology is immediate, not when it's most convenient or when you just can't avoid it any longer. Day-apologizing is not frowned on like day-drinking. 

And now where are they? Off on a all day little trip together. DH said "we'll talk later becuase I don't want to fight in front of the skid." (TM) Yup, this is where the skid is learning avoidance. By example. More important not to keep the kid waiting and to make sure he thinks things are okay. Also, there's no fight if you just proactively say you talked to him and you made him apologize right away.