Peda is a very common slang word in Mexico that you won't find in a textbook. It can mean a 'party' (specifically one with a lot of drinking) or it can refer to the state of 'drunkenness' itself.
The song's title, "EN LA PEDA", and its opening line, "Mis compas en la peda", immediately sets the scene. It translates to 'At the Party' or 'While Drinking', telling us the singer is with his friends, trying to drink to forget a lost love. Learning slang like peda is key to understanding the real-world context and emotion in popular music.
Junior H leans straight into the messy side of heartbreak on "EN LA PEDA", and he is not pretending to take the high road. He kicks things off hanging out with his friends, who all know he is lying to himself: "Mis compas en la peda / Ellos no creen que olvidarte pueda" ("My buddies at the drinking party / They don't think I can forget you"). In Mexican slang, a peda is simply a heavy drinking session. While his ex seems totally unfazed ("Tú estás como si nada" ["You're acting like it's nothing"]), he calls over the waiter for another bottle, hoping that this next drink will finally wipe his memory. He even jokes that he used to be a good kid before this breakup wrecked him: "Antes de ti yo sí era buen muchacho" ("Before you, I really was a good boy").
The song turns brutally honest—and frankly, a little cold—when he talks about his rebound attempts. He boasts, "Chingo de viejas conocen mi cama / Y al sordo no sé ni cómo se llaman" ("A ton of women know my bed / And frankly, I don't even know their names"). Here, chingo de means "a hell of a lot of," while al sordo is casual slang for playing dumb or staying quiet about something. Instead of healing, he realizes he is just passing his misery onto other people: "Qué factura les dejaste tan cara / Pobrecitas, las dejé bien dañadas" ("What an expensive bill you left them / Poor girls, I left them so damaged"). By the time he is drunk enough to swear he will pull down the moon for her ("Ya pedo me entró la de ir por la luna" ["Now that I'm drunk, I got the crazy urge to go get the moon"]), you know he is stuck in a loop of alcohol, bravado, and a smashed heart ("mi cora está deshecho").