If you are discrete and both white and European/Western, you could probably get away with it. As someone else pointed out, if a neighbour is offended (either with or without cause - it doesn't matter) and reports you, then you'll have problems up to and including arrest and deportation. And before anyone says that won't happen to me I'm ___________ (fill in nationality) - yes it can happen, I've seen it first hand.

Your SO will need sponsorship to enter the country and to stay unless their passport is one which allows them to enter without it - however, in that case, they still could not list your name and address as where they will be staying, better to use one of the hotels as their destination?