* "Porque no quieres hablar en espanol" means "Why don't you want to speak in Spanish?"
* "Esta bein" is a colloquial way of saying "That's okay" or "It's fine" in English.
* "Perron" is slang that can be interpreted in different ways depending on the context. It can be used as a term of endearment, like "dude" or "bro", or it can be used to express something is "awesome" or "cool".
Putting it all together, the sentence roughly translates to:
* "Why don't you want to speak Spanish? It's okay, bro."
The sentence implies that the speaker is trying to encourage the other person to speak Spanish, but understands and accepts their reluctance.