How do you say goodbye my sweet friend in portuguese?

Here are some ways to say "goodbye my sweet friend" in Portuguese, depending on the level of formality and closeness you have with your friend:

Formal:

* Adeus, meu querido amigo. (Goodbye, my dear friend.)

* Até breve, meu amigo. (See you soon, my friend.)

Informal:

* Tchau, meu bem! (Bye, my love!) This is very affectionate and casual.

* Até mais, meu amigo. (See you later, my friend.)

* Valeu, amigo! (Thanks, friend!) This implies you enjoyed spending time with them.

* Te amo, meu amigo! (I love you, my friend!) This is very close and affectionate.

You can also choose a phrase based on the context:

* Que bom te ver! Até a próxima! (It was great to see you! See you next time!)

* Foi um prazer te conhecer! (It was a pleasure to meet you!)

* Que a vida nos encontre novamente! (May life bring us together again!)

The best phrase to use will depend on your specific relationship with your friend and the situation.