Sornero is a Colombian slang term, particularly from Medellín, meaning 'stealthy' or 'sneaky'. It's not a common word in standard Spanish, making it interesting and unique to this song's regional flavor.
In the context of the song, it's used to describe a car that is 'sornero', implying it's powerful and fast, but also discreet or ready for action without drawing too much attention. It adds a layer of street credibility and local color to the lyrics.
"Sornero" is Medellín slang for keeping something on the low, and that is the whole mood of this song. Blessd lays out a night with the woman he is seeing: the bike already warmed up on the corner, the apartment perfumed from the floors to the ceiling, her phone switched off, and nobody else needing to know where either of them is.
Most of the track is him telling her how he sees her. He notices the outfit she picked, calls her the only woman he would let steer his life, and is openly explicit about how the night is going to go. The language is thick with paisa slang, so you will meet words here that rarely turn up in a textbook: "qué chimba" for how good something is, "mela" for nice, "mero tote" for a knockout.
Running underneath the romance is the other half of his life. He calls himself a bandido and asks whether she would still love him if he ended up behind bars. Her answer, as he tells it, is that she would take the conjugal visit. That mix of tenderness and the street is what the song is actually built on.
The spoken outro drops the beat and the bravado. People say a lot of things about me, he tells her, and there is gossip at every turn, but I am only ever with you. He signs off with shout-outs to Barrio Antioquia, the Medellín neighbourhood he came up in, and to Los Money Makers.