Precisely.
But be smart about it.
Learn it on the sly, and don't let on that you understand the language.
Then, don't speak spanish. Just listen...
When you find yourself behind enemy lines, sometimes it's best to just play dumb, and listen. People will say one thing when they think you can understand them, and something completely different when they think you're just a dumb gringo who can't understand what they're saying.
Personally, I'd prefer to know what they're saying behind my back. And if I'm "just a dumb gringo who doesn't understand spanish", then "behind my back" discussions will happen right in front of my face.
So yeah, I will be learning spanish. You can make book on it.
But I won't be speaking spanish.
No, you have real life confused with that Seinfeld episode where Elaine brought Frank to bust her Korean manicurists.