One of the best parts about being multilingual, especially in languages not widely spoken, is that, when you act 'normal' around them and they say bitchy or nasty things about you, it's so satisfying to turn around and address them in their language directly, or passively-aggressively use a phrase to your travelling partner in the local language like, "They're so rude here, aren't they?!" I love the reaction that gets.....
Also, when travelling abroad, I've gotten out of some uncomfortable situations by pretending not to be British but Swedish instead.