This sounds odd to me. We would be much more apt to say "Whose wedding is it?" as marriage is a state rather than an event.
Wedding would be 'trouwerij', though.
This could be a rhetorical question. Then, I guess, it would make sense.
I'm fairly sure the use of question marks aren't dependent on rhetoric. And in some cases that would make it difficult to tell if it were a question or not.
In English, "marriage" is also an event. But, personally, I prefer "wedding" in this context.
"bruiloft" = wedding. The ceremony/celebration when two people get married.
"huwelijk" = marriage. The union between two married people. Lasts from the wedding until the divorce (or death).
Huwelijk means wedding, but was marked wrong by DL. Reported.