Agüitado is a colloquial Mexican Spanish term that means 'down', 'sad', or 'bummed out'. It's a more expressive and less formal way to describe feeling low than simply saying 'triste'.
In the song, the singer uses it to convey a sense of melancholy and loneliness after a breakup, setting the emotional tone for his reflections on almost forgiving his ex. This word adds a touch of authentic, everyday language to the lyrics.
Have you ever been so close to doing something you know you shouldn't? That's exactly what Banda MS is singing about in "Labios Resecos"! Our singer is feeling down and lonely, admitting, "Me sentía solo, un poco agüitado / Y casi te llamo" [I felt alone, a little down / And I almost called you]. He's lying in bed, noticing you're not there, and almost misses you. He even says, "Me sentí los labios un poco resecos / Y casi te beso" [My lips felt a little dry / And I almost kissed you]. Talk about a close call!
But then, a sudden realization hits him! He remembers all the lies and how you hurt him, saying, "Que me lastimaste con tantas mentiras / Que tienes talento pa causarme heridas" [You hurt me with so many lies / You have a talent for causing me wounds]. He was almost ready to forgive you, even after you "Me diste en la madre yéndote con otro" [You screwed me over by leaving with someone else]. It's a relatable story of almost falling back into an old pattern, but thankfully, remembering why you left in the first place. He even exclaims, "Y pensar que casi la vuelvo a regar!" [And to think I almost messed up again!]. What a relief he didn't!