Just do what I do with the Asians I work with. If they're speaking their native language I try to pay attention like I understand them. If they all laugh, I laugh like a crazed lunatic with them. If they act shocked, so do I. They know I'm full of crap, but it's fun for me to pretend. I fake speak Laotian, Korean, Nepali, Indian and Cambodian. I can fake speak a little Thai as well.