Tusa is a popular slang term used in many parts of Latin America to describe the intense feeling of heartbreak, sadness, and bitterness after a relationship ends.
In the song, TINI sings, "Pero esta tusa es tan grande" (But this heartbreak is so big), expressing an overwhelming pain that is going from bad to worse. It's a fantastic and very current word to know if you love modern Latin pop music, as it perfectly captures a common theme in today's hits.
Ever been in a relationship that was going great and then suddenly... wasn't? That's exactly what TINI is singing about in "Cupido." She's looking back at a failed romance and trying to figure out where it all went wrong. She asks, "¿Qué nos pasó? / Que cuando estábamos bien se complicó" (What happened to us? / When we were fine, it got complicated). Instead of just being sad, she's frustrated and places the blame squarely on the god of love himself, declaring, "Cupido tiró la flecha y la cagó" (Cupid shot the arrow and screwed it up).
Throughout the song, TINI details the pain of the breakup. She admits that the nights are the hardest and that she still misses her ex: "Si yo te extraño / Te extraño por la noche" (Yes, I miss you / I miss you at night). She even tries the old advice that a new love can help you forget an old one, referencing the saying "un clavo / Siempre saca otro clavo" (one nail / always takes out another nail). But for her, it's not working. This love was an "amor esclavo" (slave love), and it's proving impossible to forget.