Arrepio translates to "shiver" or "goosebumps." It's a vivid word that describes a physical reaction to strong emotion, often associated with pleasure, fear, or excitement.
In Maria Rita's song, she uses arrepio to express the intense physical sensation she feels when she kisses her lover. She sings, "É só beijar tua boca que eu me arrepio" (It's just kissing your mouth that gives me shivers), highlighting the powerful, almost overwhelming, physical and emotional connection she has with this person.
Maria Rita opens with a confession that sounds like defeat: "Eu tentei, mas não deu pra ficar sem você" (I tried, but I couldn't stay without you). She went looking for someone else, got sick of it ("Enjoei de tentar", I got fed up with trying), and admits nobody could "assumir teu lugar" (take your place). Enjoar literally means to feel queasy, so she is saying the search for a replacement made her a little sick.
Then the song stops sulking and starts inviting. The chorus is pure persuasion: "Se tiver acompanhado, esquece e vem" (If you're with someone, forget it and come) and "Se tiver hora marcada, esquece e vem" (If you've got an appointment, forget it and come). She wants to watch "a madrugada e o sol que vem" (the small hours and the sun that's coming) together, because "uma noite não é nada, meu bem" (one night is nothing, my dear). The title line says it all: she has dreamed of joining "teu corpo, meu corpo, num corpo só" (your body, my body, into one single body). It is cheeky, warm and very Brazilian, and a great song for practising the command form vem (come).