"I don't like it when you're mad at me, baby."
Here's a breakdown:
* "No me gusta" means "I don't like"
* "cuando estas molesto conmigo" means "when you're mad at me"
* "nena" is a term of endearment, similar to "baby" or "honey"
The phrase expresses a feeling of discomfort or sadness when the speaker's partner is upset with them.