Celoso means "jealous." While it's a common emotion, its placement in the lyrics makes it particularly striking and relatable.
The singer admits, "Y estoy celoso atrás del hielo de tu vaso" (And I'm jealous behind the ice of your glass). This vivid image of hidden jealousy, observing from a distance, adds a layer of intrigue and vulnerability to the song, making it more than just a simple declaration of emotion.
Abraham Mateo builds this song around one image: a guy at a bar, smiling on the outside while everything falls apart underneath. He names it outright in the second verse: "Que tengo el síndrome del joker" (I've got the Joker's syndrome). That line is the whole song, laughing in public with a wrecked person behind it.
The story is an ex he can't let go of. He pictures her with someone new, jealous of a man he only ever calls "él," and replays the relationship over a drink at the bar: "Ahogando recuerdos, maldito el momento que me dio por ti" (drowning memories, damn the moment I fell for you). The hook says it straight: "Riendo y llorando sin poder dormir" (laughing and crying, unable to sleep). It's not a metaphor bolted on top. That contradiction is the actual state he's describing for three minutes, and it's why the title works as a diagnosis rather than a mood.