Help with movie title please!

I have checked all of the episode lists I could find on Google and came up with nothing.
Ok, its low budget horror/sci-fi in the 80's
If I recall, most of the film takes place in a 2-story cabin in the woods.
Nubile girls and horny boys get killed every time someone goes outside.
Cops ( ranger, sheriff) come to visit.
There's a basset hound dog.
There's a pseudo pajama party that ensues, replete with cut off t-shirts.
I hope IM not confusing this with another movie, but something tells me there's this little impish creature, really fake looking.
I think near the end some blond alien seduces one of the boys, not sure.