Hi @Sander150
I understand your frustration - you're trying to match the use of the space with the booking, but I think you'll risk making guests unhappy if you lock a room that is shown in the listing. Guests can specifically search for listings with 2 bedrooms. When they book such a place, they expect that both bedrooms will be available.
The way I understand it, you price your listing per guest, and some guests book for just one person and end up being more. This can sometimes be innocent: they do a quick search with the default setting of one guest and end up booking before adjusting the number of guests. Whenever I see a booking for 1 guest, I ask whether this is correct (even though I charge per unit, I still need to set things up for the correct number of persons). You can consider also asking this question at the time of booking and doing a "change reservation" request if they say they will be more (which will then adjust your price). Some hosts use external cameras to monitor the number of guests, although this still leaves you with the problem of having to judge whether visitors stayed overnight, and having to decide what to do about it. Alternatively, you can change to a per-unit charge (which has the disadvantage that your place may be expensive for single guests).
In any listing with more than one bed, a host may sometimes wish they could "protect" the unnecessary bed(s) from being used by a small group. However, it's probably best to avoid locking a room that guests may expect to use.
