And make sure you use a gag to ensure that there are no screams...

I would say the 'my house, my rules' mantra works here. Yes, even on mother in laws

Do you have a spare room (or a basement/cellar/attic/garage) that can be soundproofed and locked so that no one is allowed in there apart from you? A bit of conversion work on a spare room to make a 'dungeon' may offset the cost of hotel rooms. And if you are clever about it you can not decorate/furnish it so much as a 'dungeon' (i.e. keep all the fixtures and fittings discrete) and double it as something else - a workroom, storage room, office or (given that your husband is a musician) even a recording studio/rehearsal room which will explain the soundproofing...