Amargura translates to "bitterness" or "sorrow". It's a strong emotional word that stands out in the lyrics.
In the song, Milo J sings, "Sos la única que mata mi amargura" (You're the only one who kills my bitterness). This line beautifully expresses how the person he's singing about brings him immense joy and relief from any sadness or hardship he might be experiencing, making her presence incredibly impactful.
Milo J's "Cuando Estas Vos" is a super sweet declaration of love and devotion. He's completely smitten, telling this person that when they're around, "llora la luna" [the moon cries], because even the moon is jealous of their beauty! That's some serious flattery.
He promises to be everything for them, saying, "En esta guerra seré tu soldado, seré tu espada, también tu armadura" [In this war I will be your soldier, I will be your sword, also your armor]. It's clear he's ready to protect and support them through anything. He even admits he wasn't looking for a relationship until they came along, thinking love was just a joke, but now he's happy just being with them, no regrets, "Porque yo fui feliz así de simple" [Because I was happy, just like that].