Quedantes is a popular Mexican slang term for the people you are casually dating, similar to a 'situationship' in English. The word comes from quedar, which means 'to meet up'.
In the song, Natanael Cano sings about his love interest's other suitors, from businessmen to traffickers, calling them her quedantes. He isn't intimidated, confidently stating that she'll be with him in the end. It's a perfect word for understanding modern, informal dating culture in Mexico.
This song is a massive declaration of love for a woman with seriously high standards. Natanael Cano and Óscar Maydon describe a girlfriend who only wears top designer brands like Yves Saint Laurent and Dior. She's so glamorous they compare her to pop royalty, calling her a modern-day Madonna and Lady Gaga: "Tú eres Madonna en la actualidad / Mi güerita flow rockstar" (You are Madonna today / My little blonde with rockstar flow).
He's completely devoted and willing to spend whatever it takes to keep her happy, buying her a Birkin bag and asking "¿Cuántos Rolex te ocupo comprar?" (How many Rolexes do I need to buy you?). He even sends money to her parents! But it's not just about the money. He says she has tamed him, singing "Tú domaste mi instinto animal" (You tamed my animal instinct), and in the end, all she asks for is "Un besito nada más" (Just a little kiss).