"Vi er i bryllupet deres."
Translation:We are at their wedding.
I would suggest that perhaps "We are IN your wedding" should not be accepted as an answer, since (and maybe this is just my personal understanding) being AT a wedding and being IN a wedding are to very different things.
To be clear, being AT a wedding would mean attending as part of the audience. Being IN a wedding would mean being the bride, groom, a member of the wedding party, someone who takes an active role in the ceremony itself.
I don't know if this is a cultural thing but I thought it was a point worth bringing up at least.
Your understanding is correct (at least as far as American English). Is there a way to make this distinction in Norwegian?
Yes, this is a good point, and I took it the other way, which is a distinct meaning. So - what is the correct way of saying you are IN the wedding? "Jeg er med i bryllupet deres?" "Jeg blir med...?" "Jer er medlem med bryllup seremoni?" Noen annet?
You could say "Jeg er (med) i brudefølget ditt/deres", but I can't say that's something I hear very often.
In most scenarios you would refer to your specific role (best man, toastmaster, etc) instead, and if you're part of the immediate family then it's probably implied.
If you are talking to one person, it is clear. If you are talking to more than one person, hopefully it will be clear from context.
Forgive my stupidity but I still don't understand how the context of talking to an individual makes it clear.
If I alone am talking to one person and I say it, then it's clear that I mean us two. But let's say that a friend and I are talking to a single other person. Context doesn't really make it clear. Is it the wedding of the person we are talking to, or someone else?
You're right, I wasn't very clear. Talking to one person, it would be "bryllupet ditt" if you meant the person you were talking to, so if you used "deres" it could only mean "theirs" and not "yours(plural)". If you are talking to TWO people, "deres" could be either "yours" or "theirs" but hopefully from the context of the conversation, it would be clear. So, in the case of this exact sentence, if you were talking to one person, "deres" could only mean "their" but if you were talking to two (or more) people, it could mean either without clarifying context.
I think that technically marriage is the state that they are in after the wedding.