They are, its just that the rooms are identical to your home, so there is a chance they will be mixed together.
But in general they would always be there if your current idle event is sleeping since every event is sort of tied to where they are, like Kitchen and shower but currently there is no sex scenes in the kitchen. (At least i have not seen any)
But otherwise they dont always appear in their homes if you have them as Farmhand as they would more be at the farm or roaming the park or store.