That we aren't staying in the complimentary room for the bride and groom, and let my bridesmaid have it instead?
We would rather go home(!) and not have the morning after with family etc. The room is just a standard double not a fancy one.
I kinda feel like I should tell them but I don't want them to say my bridesmaid has to pay for it if we aren't having it 
They would know who was staying in it on the day, I should probably tell them today though (nearly a week in advance), shouldn't I?