A donkey punch is a sex act and is described at wikipedia as "a slang term for a potentially lethal sexual practice sometimes performed during anal sex. The purported practice involves the penetrating partner punching the receiving partner in the back of the head or neck...allegedly causing the receiving partner's anal passage to tense up and increase the pleasure of the penetrating partner."
Now I know what you're thinking and yes there is one performed in the movie and it's lethal as well. This unleashes a whole chain of events not so pleasant for the characters in the movie...

Donkey Punch is a low budget thriller mostly taking place on a yacht. 3 British girls on Holiday in Spain join 3 young men who they meet at a party. They're part of a crew of an expensive yacht. The girls join the boys and end up on the yacht where they're joined by one of the guys' older brother who is in charge of the crew. All is fun as they are on open sea doing drugs and drinking alcohol. As the partymood comes to an end the hornyness starts and nothing short of an orgy is starting below deck. Now I must mention that this is quite an explicit orgy. I've seen softporn movies tamer than this. Apart from actual penetration you get to see the whole deal here. Penisses, asses, breasts and vagina's are all over the place in this scene.
It is at this orgy one of the male characters performs a Donkey Punch on Lisa (Sian Breckin) who ends up dead. This gives us a situation where the boys need to get rid of a body (we'll just say she fell of the boat) and the girls have just lost a friend.
Add to the mix the existence of a videotape in which the fatal blow is shown and you've got 6 people who all of a sudden have their own interests to look out for.

Murder and mayhem ensues.

Donkey Punch is a tight and for the first half hour sexy thriller. The small budget never shows through although it is obvious that that is one of the reasons it basically all takes place on a boat but it helps the movie, like the warehouse worked so well for Reservoir Dogs. From the moment the murder takes place it all becomes very questionable who will live and who will die. There are some unexpected twists and turns but the survival of one person is clear the moment she first is on screen. She's your typical slasher survivor.

Donkey Punch is an intriguing little thriller and it should serve as a launchpad for it's unknown cast and director to bigger things.

Sex, lies and a videotape