Humanoids Feed by Sucking People Through Their Hose-Like Mouths

by Vix
(Sofia, Bulgaria)

I'm looking for the title of an 80's or early 90's horror movie where humanoids feed on people by sucking them with their prolonged hose-like mouths.

In one scene, a boy at a party sucks someone in a kind of feast-orgy. The main character is a teenage boy adopted by a family of the 'suckers'. He kills one of them at the end (at the same party?) by kicking them in the groin.

I suppose this movie is generally stupid, but I just have to watch it again. I highly appreciate it if any of you can help me.

Thanks!