Te mudaste comes from the verb mudarse, which literally means 'to move house'. While it's a common verb, Bad Bunny uses it here in a very clever and poetic way.
In the song's hook, he sings, "a mi mente te mudaste", which means 'you moved into my mind'. He's creating a powerful metaphor: this person isn't just a fleeting thought, they've permanently 'moved in' and are now living in his head. It's a perfect example of creative wordplay in music!
Bad Bunny hits you with pure, unfiltered nostalgia for a passionate hookup in this track. He cannot get a past lover out of his head, literally claiming: "Desde que te desnudaste a mi mente te mudaste" (Since you undressed, you moved into my mind). He spends his time staring at old intimate photos, reminiscing about how they couldn't even make it to the hotel room before getting physical in the car ("Nos comimos en el carro, al cuarto ni llegamos" [We ate each other up in the car, we didn't even make it to the room]). He is frantically searching dating apps to track her down, wondering if she went back to her ex.
What makes the track so catchy is the direct Puerto Rican street slang and zero-filter attitude. He misses the "bellaqueo" (dirty intimacy/lust) and "perreo" (intense reggaeton grinding). He is not even asking for a traditional relationship; he is fine being the side piece ("chillo"), joking that "Tú no eres monja ni yo monaguillo" (You are not a nun and I am not an altar boy). From smoking a "blunt" (weed cigar) on a hotel balcony to suggesting she could get rich ("millo", short for millionaire) on OnlyFans, he drops vivid, everyday details to show how obsessed he still is with replaying that night.