Smudge Fuck 

To ruin something through excessive handling.

I don't lend out my porno magazines anymore because they always come back smudge fucked.

Smudge Fuck by october-jones October 23, 2008

Sludge Fuck 

Reserved only for the sick and twisted. A sludge fuck entails having sexual intercourse atop the deficit of each of the members involved (no pun intended). The warm gooey goodness spreads all over the participants and it somehow arouses them. Yikes.

Why let your shit go to waste!? Try sludge fucking!

Sludge Fuck by The Alchoholic Insomniac November 7, 2004