Where to host a discreet party

I'm in town for my cousin's wedding and I'm looking for a decently classy place (preferably near Belltown or Fremont) that would have a private room available to rent that would allow us to host a nude model. Maybe allow us to purchase some booze as well. Really last minute, but ideally it would be Wednesday 9/16.

Please help me make my cousin's final days as a bachelor memorable!