After they're done go upstairs and knock on the door ~ when he answers say that you're a pornographer and you live in the building. Tell them you taped the audio of their sex fest and would like to thank them for their contribution to your business, and to please allow you to buy flowers for his girlfriend/wife for being such a vocal screw.
Keep a big smile on your face and be very polite... ducking if necessary ~ and see if they're ever that loud again.
