Here are some possibilities:
* "Boca e mi" is a misspelling: Perhaps you meant something like "boca e Mimi" (Mimi's mouth) or "boca e mim" (my mouth).
* "Boca e mi" is a slang term: There might be a slang term in a specific region of Portugal or Brazil, but it's not commonly known.
* "Boca e mi" is a phrase in another language: Could this be a phrase in another language that sounds similar to "boca e mi"?
To help me understand what you mean, please provide more context or the full sentence where you saw this phrase.