to crease during sleep; or to develop indents in the skin on the facial, arms, legs and stomach area due to the folding of blankets, pillows, arms or other bed time objects
I slept in the same position all night long and now I have these creasing marks all over my arm and face...I look like Scarface.
Creasing is the sexual act of sliding one's penis in between the ass crack of another individual
"He, what would you do if you if that fat girl over there asked if you wanted to do some creasing later?"
"Dude, that's really messed up."
"No, but really, what would you do?"