The verb cundir typically means 'to spread' or 'to yield'. However, in this song, Milo J uses it in a colloquial way common in Argentina, where 'te lo cundía' suggests something 'paid off for you' or 'was worth it for you'.
He sings about a time in their relationship without fights or suspicions, implying that this peaceful period was beneficial or fruitful for his partner. Learning this word is a fantastic glimpse into real-world, regional slang you won't find in a textbook!
This song is all about that feeling of being completely obsessed with someone you're not even dating. Milo J kicks it off with a super relatable line: "Te vi, y como tonto te fui a seguir" (I saw you, and like a fool I went to follow you). From there, it's a spiral. He's thinking about this person every morning, checking his phone hoping for a text that never comes, and dealing with it through "Otra borrachera, otra madrugada" (Another drunken night, another early morning).
What makes it so painful is that he knows this is a bad idea. He admits, "Sólo voy a dañarme" (I'm only going to hurt myself). The most frustrating part for him? "Ni somos nada tú y yo" (We aren't even anything, you and I). He's caught up in a one-sided situation, feeling like his love is just a game to the other person. He even realizes his feelings might not be real love, but something else: "todavía te quiero pero creo que por dependencia y no por amarte" (I still want you but I think it's out of dependency and not out of love). It's a blunt and honest look at a messy, confusing infatuation.