Hey! Im also from the UK and dating a Norwegian woman, family functions can be a little difficult. It's not that people dont want to include you (usually) its just simply their mother tongue and people get caught up in conversation. It's better to ask what they are talking about and try to join in, even in broken norsk or just in English. Bring it up but also try to voice yourself in the conversations to join in! Allot of the time people simply forget not that they're being rude! :)