Someone who will "break their parents' backs" in order to keep up with expensive trends. They hound their parents to buy them trendy clothing/items in order to keep a high social status or in other words, make them look wealthy.
Yoongi: Did you hear that Jungkook has a new expensive jacket?
Jimin: Yes, his mother's money has gone down the drain for it.
Yoongi: Jungkook is such a spine breaker.
"The fourth wall" is an expression stemming from the world of theater. In most modern theater design, a room will consist of three physical walls, as well as a an imaginary fourth that serves to separate the world of the characters from that of the audience.
In fiction, "breaking the fourth wall" often means having a character become aware of their fictional nature. This can range from your character advising you to "Press X" in a tutorial all the way to Psycho Mantis reading your memory card and mentioning the other games you've been playing. However, the most direct violation of the fourth wall would be a character openly acknowledging they are in a video game or even directly speaking to you, the player, instead of to your character.
(Jak 3:)
Monk: This isn't a game!
-Jak and Daxter look toward the player with confused expressions-
Your first piss in the pub, usually after 2 hours of drinking. After breaking the seal of your bladder, repeat visits to the toilet will be required every 10 or 15 minutes for the rest of the night.
'I broke the seal in the Flapper and Firkin bogs, after that there was no stopping me"