What is the best strategy for a multi-lingual couple to instill both the father's and mother's native languages to the child in a most "natural" and efficient way?
My wife and I have been speaking English between ourselves for the eight years we've been together since we met in the USA as international students and until our first son was born two weeks ago. Neither of us is a native English speaker; she doesn't know my native language and I don't know her native language well enough, and we are both pretty comfortable in English (though both not perfect), so we stuck with it; since six years we've lived in a country where her native language, German, is spoken, but I haven't really picked it up as my day-to-day life is in English.
Now that our first son was born we are wondering how to behave, linguistically speaking, around him. Her and I obviously have to keep talking English between the two of us because there's just no other option for us to communicate. When either of us is alone with the child then I suppose we could also speak our respective native tongues to help the child pick it up. But what if all three of us are together, such as at the dinner table? What should we speak?
My wife says we should have a mix where she speaks English to me and German to him, and I speak my native tongue to him and English to her. I feel this is very unnatural since I would like to understand what she says to him, so I feel it's more humane that we all speak English when we are together. But is this going to be harder for my son? He would then be immersed in three separate languages, which I understand makes it harder.
Right now he is still very small, so I guess it doesn't matter a lot yet, but when changing a diaper or picking him up she would speak to him some comforting sentences in German, which is obviously very natural, but if I'm there I'd like to understand those little jokes, funny nicknames and soothing metaphors as well. When I speak to him and she's there I do it in English because I want her to understand as well and then she's rebuking me and saying I must speak my native language.