Al chile literally translates to "to the chili pepper," but it's a super common Mexican slang phrase that means "honestly" or "for real." It's used to emphasize that you're telling the absolute truth, without holding anything back.
In the song, Ed Maverick sings, "Y al chile yo hasta moriría por ti" (And honestly, I would even die for you). Using this slang makes his desperate plea feel incredibly raw and authentic, as if he's cutting through the games to tell her his true feelings. It's a perfect example of how slang can add a powerful layer of emotion to a song.
If you have ever been stuck in romantic limbo, Mexican folk artist Ed Maverick writes your exact frustration here. He is completely lost in his feelings, admitting that while her kisses say yes, her actual words say no: "Tus besos dicen que tú sí me quieres pero tus palabras no" (Your kisses say that you do love me, but your words do not). He throws around very natural Mexican slang to plead for honesty, using "al chile" (honestly / to be completely real with you) and begging her to be clear ("sé concreta por favor"). He even calls himself out for being completely gullible, admitting he falls into her trap like a naive little kid: "Como bebé caigo pero sí redondito en tu trampa amor" (Like a baby, I fall right into your trap, my love).
Between sleepless nights staring at the stars and drinking away the confusion ("me he empedado tanto por tu amor" [I have gotten so drunk over your love]), he gives her an ultimatum. He swears he could make her happy if she just defines what they are, but if the games continue, he will walk away and leave the heartbreak behind at a specific neighborhood spot in Chihuahua, promising: "Yo te olvidaré desde las Fuentes de Ortiz" (I will forget you from the Ortiz Fountains).