Sibling Code 

The unspoken rule that what is said between siblings about parents or other siblings, stays between siblings. It's like the man code or the bro code, but with siblings. It's like Vegas. People who violate this unspoken rule are considered untrustworthy. Breaking the code is akin to betrayal. The phrase is never said out loud unless it is being explained to someone who for some reason did not become aware of it through osmosis or other siblings' example.

Sibling1: "Dude, you can't tell Mom I said this, but she's a little oversensitive."

Sibling2: "Mom said it wasn't nice that you called her oversensitive. Then she cried."

Sibling1: "Are you freaking kidding me??!!! Look, I thought you would have gotten the hint by now, but there's this thing called the Sibling Code..."

Sibling Code by YourSister August 31, 2013

Sibling code of honor 

An agreement between siblings to keep a secret from parents otherwise they might all get in trouble.

It's the sibling code of honor to not tell dad we were both at that party.

Sibling code of honor by Smiterm May 31, 2016

younger sibling code 

The younger sibiling shall always embarass the older sibiling and must also rat on them and tell their friends about the older sibilings secrets.

Younger brother to older brothers freinds: did you know that he has wet his bed 10 times this month? I'm required to tell you acorrding to the younger sibiling code.
The younger sibling code: the youngest sibling shot always embarrass the older sibling and must also rat on them and tell their friends about the older siblings secrets

younger sibling code by Bunyguy202 November 20, 2016