Just to warn you in advance, this is a long OP because I don't want to drip-feed, and I know how debates about bilingual families often go down on this forum. I do not resent my partner's heritage, I have tried my best to fit in with his family's way of doing things and it is still making me and my dh very frustrated/unhappy. So, I would be grateful for your advice on the following...
My dh is English with foreign heritage, and his family speak a mixture of English and the foreign language when they are together. Neither he nor his siblings have a particularly good grasp of the foreign language - their vocabulary stopped developing when they were about 10, and they haven't bothered to learn more as the language is very difficult, only spoken in one country, and they don't see very much of their relatives from over there. He and his dad (the foreign parent) generally speak the foreign language when they are together, and his dad tries to insist that they speak it on the phone and via e-mail as well. Fil does speak excellent English (it's his job), whereas dh admits that he is far from fluent in the foreign language.
Over the course of the last few years, this has caused a number of problems. Most importantly, my dh and his dad don't get on particularly smoothly at the best of times and trying to discuss difficult adult issues with a child's vocabulary means that they rarely get any closer to a resolution. It also leads to many misunderstandings, which are often only realised when one party has been stressed and upset about the situation for quite some time. There is also the problem that my dh feels that he is growing away from his parents, as he doesn't see them very often and spends all his time on the phone trying to translate the bare bones of what he is doing with his days (in a very specialised working environment) rather than really talking to them. He always looks a bit sad and deflated when he has finished a phone conversation, and says that it is for the reasons above.
I also have problems as a result of his dad's insistence on speaking the foreign language. They speak it at home whenever I am not part of the conversation (even when I am in earshot), which makes me uncomfortable and also leads to situations where I miss important pieces of information. For example, my fil will tell my dh that we are all going out at X o'clock (in my hearing), dh won't realise that he has said it in a language I don't understand (because he's so used to speaking a patois of English/foreign language), I don't realise that I need to ask for a translation because I wasn't part of the conversation, and fil clearly assumes that dh will tell me later what has been said. Result: everybody else is ready to go at X o'clock and I am in the shower/on the phone to my folks/out for a walk. Other examples would be fil complaining about mess (not ours, but we are apparently expected to deal with it) to dh in their common language, dh makes a token effort to clean up after others and doesn't pass on the message to me, and fil gets annoyed with us. As a result, I'm always on edge when I am there and constantly have to ask what's going on.
Also, the whole family make passing comments to each other in their language while we are together and it feels very exclusionary. My fil has done it in front of me to dh on at least 2 occasions when I knew it was definitely about me (not ill-intended but still not very nice), and mil even made comments to her son about a conversation she was simultaneously having with my mother at a recent birthday dinner. We don't see each other very often, and it still happens every time.
We have tried to compromise on this in order to minimise the problems. I have tried to learn their language and can string together a few phrases but it is just too difficult for me to learn (there is only one national language which is more complex, according to fil), and constantly badger dh for updates on what is going on when we're there. I also take care to give them 2-3 hours to themselves each evening when we visit, so they do have lots of time to speak their common language together without me there. Dh has asked them in the past to speak to him in English on the phone and by e-mail to sort out his communication issues, and refuses to respond to them in their common language if I'm around. However, they continue to do things "their way" when we visit, and dh's request to speak only in English when communicating by phone/e-mail has been taken as a "punishment" and an "aggressive" stance by all of his family even though he did explain why at the time.
So, AIBU to think that they should respect dh's wishes to speak to him in English on the phone, by e-mail and when we are visiting them (if I am around)?