¡Fierro! literally means "iron", but in Mexican slang, it's a popular exclamation that means "Let's go!", "Right on!", or "Heck yeah!". It's packed with energy and confidence.
In "Bebé Dame," Fuerza Regida uses it at the very beginning to kick off the song and set an energetic, ready-for-anything vibe. Learning this word is a key to understanding the cool, modern slang you'll hear in regional Mexican music.
This song is a passionate, almost desperate plea to win back a lover. The singer admits their relationship is a struggle, calling it a "guerra en el amor" (a war in love), but he's determined to fix things. He's completely focused on getting her back, telling her, "Tenerte de nuevo es mi fantasía" (Having you again is my fantasy). He can't stand the thought of being apart any longer and doesn't want another day to pass where he doesn't "te vea al amanecer" (see you at dawn).
He uses a mix of romantic promises and bold demands to convince her. On one hand, he's written a poem for her and has "mil planes" (a thousand plans) for their love. On the other hand, he's very direct, saying "Bebé, lo que te pido, ven, dame / Lo que te exijo" (Baby, what I ask of you, come, give me / What I demand). He repeatedly begs her to "vente, vente, vente" (come, come, come), insisting he knows how to love her and that she never leaves his mind.