Slippery Samson
First let your sexual partner smoke a bunch of heavy cigarettes, this will improve the dog like moaning later on. In the meantime you shave his/hers whole body. After that, lube your preferred forearm (till just before the elbow) with grease and stick all the shaved hair on your forearm (like a selfmade hand puppet). Next shove the hair lubed forearm, with the distinctive 3 knocks in a row knocking motion (because the bell doesn’t ring) up your partners butthole. Meanwhile spread your thumb and pinky finger and make your partner scream “WHOA WHOA” with a rusty voice like a Belgian hand puppet dog.
Stephan got a Slippery Samson last vacation, he didn’t see that one coming and was pleasantly screaming like a hand puppet dog.