Our basement IS sort of a stealth sex room/dungeon, but we don't play down there very often. When we first moved in, I installed eye bolts in one of the beams, in the perfect position to attach wrist cuffs, set between two poles in just the right place to attach ankle cuffs.
With mundane stuff hanging on various hooks around the eye bolts, it doesn't look like anything sexual/kinky, but when we take down the stuff, it works well. The only problems are that the ceiling is too low to swing a whip, and the floor is cold, which kills it for my wife. We have played down there a couple of times anyway, but we have more fun in the bedroom.
With mundane stuff hanging on various hooks around the eye bolts, it doesn't look like anything sexual/kinky, but when we take down the stuff, it works well. The only problems are that the ceiling is too low to swing a whip, and the floor is cold, which kills it for my wife. We have played down there a couple of times anyway, but we have more fun in the bedroom.