Labia literally translates to "lips", but in this context, it's a colloquial term meaning "gift of gab" or "smooth talk". It refers to someone's ability to speak persuasively and charmingly.
In the song, the lyric "Y una labia de Don Juan" (And a gift of gab like Don Juan) vividly describes the protagonist's charismatic and manipulative speaking skills, which he uses to navigate various situations, from business deals to romantic conquests. This word is interesting because it's a common idiom in Spanish that might not be immediately obvious to a learner, and it reveals a key aspect of the character's personality.
In "MX - MAD," Eden Muñoz tells the story of a man living a high-stakes, international life of luxury. The song's narrator travels from Mexico ("MX") to Madrid ("MAD"), always dressed as an "ejecutivo elegante" (elegant executive) with a bag full of euros. He describes a jet-setting lifestyle, vacationing in places like Ibiza, Dubai, and Prague, feeling like the "dueño del cielo" (owner of the sky) as he flies above the clouds.
However, this glamorous life has a dark side. The lyrics hint at illegal activities, mentioning "30 kilos," avoiding detection, and having a red notice from Interpol. The narrator reflects on a simpler, happier time riding his bicycle before his rise to power. The story takes a sharp turn when he is betrayed by so-called friends, leading to his downfall. He goes from a Lamborghini with Sinaloa license plates directly to prison, ending the song with a warning to listeners: "sepan que la vida es muy cortita / disfruten cada momento" (know that life is very short / enjoy every moment).