Intended behaviour: It's normal for you to see one furniture change, and rarely two. You end up normally with 2 furniture used, or rarely 3, in a given scene.
If this happens more rapidly, it's in the hands of the Skyrim engine to go right or wrong. Possibly it's an install issue or mod conflict. Or you have a corrupt save due to breaking the Golden Rule. The corrupt save is most likely.
To check for the corrupt save possibility (this can be done in 5mins):
Just as a test, start a new game (really a new one, with the new button)
Use the MCM Misc Tab, Skip Initial Story. Now you have the Love Shout and can get Nocturnal to show up
Set the MCM settings on the Encounters tab to only do Pain is Pleasure, and increase the chance to 100 so you can trigger the scene right away
If the problem is not re-created with the new game, you know it's a corrupt save. If DOES recreate, you know it's not the save, and must be an install issue. Note that if you find you have a corrupt save, you should expect many other problems to eventually reveal themselves.
Mod conflict possibility... some overhaul mods will change the behaviour of the weapons, including the whip used in this mod. So if the furniture scene involves a whip, the mod overhaul could be breaking the animations, and cause the furniture to cycle. Maybe you can adjust the overhaul mod if this is the case.