IN THE FLESH= (usually referring to a person or animal) for real, in real life, in front of me. So in this song she begins saying that, of course, she has seen diamonds many times, but in photographs or on TV, but she has never seen a real diamond. FLESH= animals are made mostly of flesh and bones. When we eat the flesh of an animal we call it "meat". We have all seen Obama, Brad Pitt or Napoleon on TV or paintings, photos, etc., but have you ever seen them "in the flesh"?
I CUT MY TEETH ON...= My first experience with... / When babies first grow their teeth, they have to cut through their gums to come out, so we say that they "cut their teeth", and then they are ready to start eating solid food. If you say that you cut your teeth on something (cut- past tense) you mean that you started getting a skill or an experience of it (probably when you were very young). Since she is talking about diamonds, what she says here is that she has never seen a real diamond, and her first experience of a diamond was from watching wedding rings in the movies.
I'M NOT PROUD OF MY ADDRESS= I live in a poor area and I feel ashamed that people may know that. Or maybe she simply means that she lives in a very normal neighbourhood, so she has no reason to be particularly proud of it.
TORN UP= (tear-tore-torn) Destroyed, ruined; in a very bad condition.
NO POST CODE ENVY= The Post Code (BrE Zip Code) is a number or number-letter combination that is added at the end of a postal address in many countries so the mail service can automatically know to which area that letter must go. A post code refers to a small town or a particular district in a city. ENVY is the feeling of wanting to have the same as somebody else's have. Since she lives in a poor area (a torn up town), nobody will feel envy at her post code.
EVERY SONG IS LIKE...= Today, all the songs are about (those things she says, which are things about richness, luxuries and wild life). The phrase TO BE LIKE means "to say", e.g.
- I said 'hello' and she's like 'go away' = ...and she told me: "go away"
GOLD TEETH= A horrible fashion followed by some rich singers (especially rappers) consists of wearing "grillz", a kind of false set of teeth layer made of gold (see picture)
GREY GOOSE= A premium vodka brand name.
TRIPPING= If you trip, you knock something with your feet, stumble and probably fall down. Tripping in the bathroom (after drinking Grey Goose) means that they are very probably is a bit (or a lot) drunk. // Another meaning (slang) of TRIP is to take hallucinogenic drugs, such as LSD.
BLOOD STAINS= /blʌd steɪnz/ A mark of blood. A reference to fights, I suppose?
BALL GOWNS= A dress girls may wear at a ball (see picture). A BALL is a very refined party where people dance (not like a disco, but a party for high society or similar).
TRASHING THE HOTEL ROOM= "Trash" is "rubbish, litter, something useless to throw away". If you trash a place, it means that you throw things everywhere and leave the place untidy, dirty and messy. In the song, TRASHING THE HOTEL ROOM means that a wild party took place there.
WE DON'T CARE= It's not important for us, we don't worry about it.
CRISTAL= A very expensive champaign.
MAYBACH= A very luxurious (and expensive) brand of German cars.
TIMEPIECE= A watch. (slang) a very expensive watch.
LEASH= A string, rope or strap you may use to take your dog (etc) out for a walk. To be "on a leash" is to be tied with a leash. Many people walk with a dog on a leash. Having a TIGER ON A GOLD LEASH is a strong symbol of extravagant ostentation (see picture)
CAUGHT UP= (catch-caught-caught) Completely involved with someone or something, tangled. If you are caught up in a situation, it is very difficult for you to get out of it.
YOUR LOVE AFFAIR= A love affair is a romantic or sexual relationship with somebody, often short and intense. But in this song, "your love affair" is your love for luxury.
ROYALS= People who are family of the king or queen.
IT DON'T RUN IN OUR BLOOD= Royals are part of the king's family, so if you are a royal, the king's blood runs in your veins, but if you are not, it doesn't. Using DON'T for the 3rd person singular is grammatically wrong, but not uncommon in colloquial conversation.
LUX= (coll.) Luxury.
AIN'T= (slang) /eɪn(t)/ Isn't.
CRAVE= If you crave for something, you really want it.
BUZZ= (coll.) Anything that creates excitement or stimulus. (also: alcohol. But not here)
RULER= A person who has the power to rule (govern) other people, especially to rule a country (like a king).
QUEEN BEE= A girl who, usually in a high school setting, is the "leader of the pack." she doesn't always have to be the prettiest, but she is extremely confident, and because she thinks she's hot, others do too and everybody likes her (and/or envies her). / Literally, the queen bee is the bee which breeds all the other bees in a colony, the most important bee in a beehive (see picture)
I'LL RULE= I will reign, govern, have the power. Also, if you rule, it simply means that you are the best and people admire you: Elvis Presley rules! (just an example)
WE'VE CRACKED THE CODE= We've decyphred the code. It means they've figured out how to enjoy life without getting caught up in the obsession with money the song rails against. Enjoying life seems to be: Time with friends and going to parties while being frugal by doing things like taking public transportation and being careful with your dollars and cents (see next line). This is as opposed to obsessing over luxury brands and goods.
WE COUNT OUR DOLLARS= We are very careful with the money we spend (because we don't have much).
WE'RE BETTER THAN WE'VE EVER DREAMED= Not even in our imagination could we think we would be so rich and wonderful. // Here we have two pairs of lines beginning with "ooh, ooh, oh, ooh". In the first one, it is the newly-rich singers talking (we're better than we've ever dreamed and I'm in love with being queen). In the second one, it is Lorde talking (Life is great without a care; we aren't caught up in your love affair)
WITHOUT A CARE= If you live without a care, you have no responsabilities or problems.