How would you feel if they were speaking another language?
If you had guests in your home and they constantly spoke in a different language that you didn't understand. They are able to speak your language and they do talk to you on occasion about very general things like, "is it cold outside today?" And "where should I put this?" (Referring to an item they want to put away but don't know where it goes). Just very general, impersonal things. But they always speak to each other (referring to husband and wife) in their native language. They do it right in front of you. They do it all day. They even whisper to each other at times, right in front of you, in their native language. Would this make you feel left out, uncomfortable since it's your home and you may feel like the stranger, or would you not care? Mind you, they are guests for a few weeks, so you have to deal with this for awhile.