Peidando literally means "farting". However, in Brazilian Portuguese slang, especially in this context, it's used to mean "shitting bricks" or "being scared stiff".
MC Cabelinho uses this vivid and somewhat crude slang to convey that his enemies are terrified of him. He sings, "Sei que você 'tá peidando, que 'tá morrendo de medo" (I know you're shitting bricks, that you're dying of fear), emphasizing their fear in a very impactful and memorable way.
"Carta Aberta" feels like a raw diary entry in rap form. MC Cabelinho opens up about keeping his eyes on his own path, blocking out gossip and envy while revealing the hidden cost of fame. He admits that success can be lonely and that the past cannot be rewound, yet he stays laser-focused on his dreams and refuses to let anyone belittle him.
The second half flips from reflection to warning. Cabelinho addresses those who mocked him, promising payback now that the tables have turned. Beneath the tough talk you still sense vulnerability: he wishes an old love well and trusts time to heal wounds even as he plans his revenge. The song is both a confession and a challenge—part motivational speech, part cautionary tale about the shadows that follow stardom.