Infiele' is a colloquial, shortened form of "infieles," which means "unfaithful ones" or "cheaters." It's a strong word that directly addresses betrayal in relationships.
In the song, Jay Wheeler sings, "Las que me fueron infiele' / Gracias a Dios ya no tengo quien me cele" (The ones who were unfaithful to me / Thank God I no longer have anyone to make me jealous). He uses this word to reflect on past heartbreaks and how his newfound success has freed him from those painful experiences, making it a pivotal word in his narrative of personal growth.
"Yo No Cambié" is Jay Wheeler's answer to anyone who thinks money changes a person. He opens by separating himself from the fame that found him rather than the other way around — "Yo no fui el que busqué la fama" ["I wasn't the one that looked for fame"] — and spends the rest of the hook drawing the same line over and over: "Yo no cambié, mi vida fue la que cambió" ["I didn't change, my life was the one that changed"]. The circumstances are new — private planes, songs hitting a million streams, a car doing two hundred miles an hour — but he's careful to credit the shift to what happened around him, not to who he is.
The verses fill in why that distinction matters to him. He remembers starting from nothing, with nobody trusting him and no money behind him, and names the fair-weather people who disappeared once things got hard — "Falsas amistades de mi vida se fueron" ["Fake friends left my life"]. That history is why the gratitude in the closing verses reads as earned rather than routine: he thanks God, thanks his mother's prayers, and thanks the fans for the respect they give his music, before signing off with the name of the album itself, Platónico.