Arda comes from the verb arder, meaning "to burn". While that's its literal meaning, it's used here in a very popular and sassy slang expression.
In the song, the line "Que no te arda estar sin mí" is a defiant taunt that means "Don't let it burn you to be without me." It's the perfect way to say "Don't be salty" or "Don't get bitter" in Spanish, capturing the song's fiery attitude.
If you need a masterclass in drawing a boundary, Grupo Firme gives you the ultimate breakup anthem with "Ya Supérame" (Get Over Me Already!). The track jumps straight into the drama with zero patience left. The singer mocks an ex who refuses to take a hint, asking with total sarcasm: "¿Qué parte no entiendes cuando te digo que no? ¿La N o la O?" (What part do you not understand when I tell you no? The 'N' or the 'O'?). From there, the message is crystal clear: you are blocked everywhere ("de todos lados ya te bloqueé"), the story is erased, and they are genuinely happy living life without you.
What makes the song so fun and punchy are the sharp, everyday Spanish expressions. When Grupo Firme tells the ex "tienes que saber perder igualito que sabes mentir" (you have to know how to lose just like you know how to lie), it hits like a direct reality check. They wrap it up with the fiery line "¡Que no te arda estar sin mí!" (Don't be so bitter about being without me!), using the verb arder (which literally means "to burn" or "to sting") to call out someone who is visibly stinging with jealousy and spite. It is loud, direct, and completely unapologetic about moving on.