I saw a cut version of this movie as a kid from a Scandinavian cable channel called FilmNet in 1991-1992 or so.
Here is what I remember of it:
-A woman, perhaps the owner of the motel or hotel or some other building with lots of rooms lets some people look in to the rooms where other people are having sex.
-In one room there is a hyper sexual woman who wants to fuck this one man over and over again. The man had short(?) moustache and dark hair, the woman might've been blond. The man gets really really tired and is sweating a lot.
At one point the building owner opens the door to that room. The man is too tired to do anything but his partner keeps on pulling him to fuck with her. The man stretches his arm towards the owner so that she would get him out of there while his partner is pulling him. The owner closes the door leaving the couple inside.
-Near the end(?) the owner lady talks to a perhaps an older man, who might be balding or a bit chubby if I remember correctly. I recall they are on a sofa and the man might say something that he'd like to fuck the woman.
The woman says something like "but I thought you were gay" to which the man replies that he goes both ways, again if I remember correctly.
-It might've been shot on video. In my mind it doesn't look like film quality. So, it's quite certainly made sometime in 1985-1992.
It isn't Squalor Motel or Motel Sweets.
At another forum someone suggested Butt's Motel 2, but I can't find the film anywhere. I can't even find any screenshots of it so I don't know if it's the one. I know it's not the first Butt's Motel though.
I've searched for this one for ages and bought several films to see if it's the one but with no luck yet.
I also bought the FilmNet magazines from those years and searched for every adult movie they showed but at some point the magazine stopped showing the titles of the movies in the magazine (at least in Finnish version) so I found nothing.