Slang term for defecating, for pooping or the laying out of turds. Hence the term 'cable laying'.
Many slang terms exist for one pooping in sexual acts. This is just one such term, where a person lays a trail of poop on another, or is watched doing it.
Noteworthy: Many of the terms used for taking a poop, or defecating, have double meanings, and is as varied as is the culture differences for many words. Some terms can be used to indicate one's preferences, other than using more well know words like SCAT.
Terms have been coined for when one poops after anal sex, such as shoot the plug, blowing out the plug, abort, and others.