Empeliculaste comes from the Spanish word "película" (movie). It's a colloquial and very expressive term that means to "get all dramatic," "get carried away," or "imagine things like in a movie."
In this song, the artist uses it to tell the person that they took the casual encounter too seriously, imagining a deeper relationship that wasn't there. He sings, "Tu fuiste la que te empeliculaste" (You were the one who got all dramatic/carried away), highlighting the contrast between his casual intentions and her heightened expectations.
Get ready for a super direct and a bit cheeky track from Kevin Roldan, Kalido, and HIT$ MUSIC! "Te Empeliculaste" is all about a guy who thought he was just having a good time, but the girl he was with started to catch feelings – or as the song puts it, she "empeliculaste" [got all cinematic/made a movie out of it].
He's pretty blunt about it, saying things like "Realmente lo que yo quería era pasar el rato, Y que solo vaciláramos" [Really what I wanted was to hang out, And just chill]. He even reminds her, "Tu fuiste la que te empeliculaste, El día que te lo metí en el asiento de atrás" [You were the one who got all cinematic, The day I put it in you in the back seat]. He's got a girlfriend, so he can't commit, even though he admits "la verdad cosita vos me encantaste" [truthfully, little thing, you enchanted me]. It's a fun, no-holds-barred look at a casual encounter that one person took a little too seriously, all set to a catchy beat perfect for dancing.