El Traje (The Suit) is Camilo looking in a mirror and not recognising the man in it. He won't talk to him, "porque no hablo con desconocidos" (because I don't talk to strangers). Still, something in that face reminds him of a kid who rode his bike around the neighbourhood. Same mouth, different smile: the old one lasted and "no iba tan deprisa" (wasn't in such a hurry), and it shone "por cosas sencillas" (over simple things).
So he asks whoever sees that kid first to pass on a message: "Dile que no" (Tell him no). Don't get on "ese avión que está hecho de mentiras" (that plane made of lies), don't trade happiness for a fantasy. The warning nobody gives him is that he'll want to come back, and the bike and his friends won't be there. The bridge is blunt about success: "Triunfas y vas a sentir que fracasas" (You win and you'll feel like you're failing). It closes on a line that sounds like an accountant's verdict: "Qué mal negocio que hiciste" (What a bad deal you made). The suit of the title never shows up in the lyrics, but you can picture it: the costume of the grown-up who made it.