A sexual position, the Fart Knocker is achieved when a man is engaging in breast coitus with a Woman but is facing the opposite direction so the man's anus is hovering above the Woman's face. While pumping the breasts, the Woman sticks out her tongue which brushes the man's anus as he humps her breasts.
I was just gonna titty fuck her but how often do you get to do the Fart Knocker with a chick that isn't a stripper?!
A fartknocker is a person that is so lame they do not appreciate a good fart. They 'knock' or 'put down' the idea of farting and enjoying it; which makes them a total loser.
The little piece of poo that is pushed out then broken off during a forceful fart. Similar to poop-nugget and shart. (It is the less wet and messy version of the shart)
"Oh man, I think I just left a fart rock in my jockey's."
"Dude, I can totally smell that fart rock you just dropped. Go to the bathroom and clean that out."