"Okay, girl, I'm leaving because..."
The full meaning depends on the context of what comes after "por que". For example, it could be:
* "Okay, girl, I'm leaving because I have to work."
* "Okay, girl, I'm leaving because I'm tired."
* "Okay, girl, I'm leaving because I have to go to the bathroom."
The phrase "bueno nena" is a casual and friendly way to address a woman, similar to "okay, girl" in English. "Te dejo" means "I'm leaving".
It's important to remember that this phrase can be interpreted in different ways depending on the tone and context. For instance, it could be used in a friendly or flirty way, or it could be used to dismiss someone.