dogflapping 

The act of pleasuring two men at the same time, without either of them knowing about the other. Simply put, the woman kneels within a large dogflap (like a catflap in a door, only larger), and men 'take' her from either end, without being able to see each other.

I was out in Oxford last week, and saw STFCBird dogflapping two tramps in Argos, near Bonn Square.

dogflapping by Tramp#1 August 6, 2004

Dogknapping 

Whenever you touch the tips of your toes on the bottom of another’s nutsack lightly

Like: Why did you just touch the bottom of my nutsack lightly

Haden: It’s called dogknapping

Dogknapping by Big daddy Haden April 14, 2018