2.) To ejaculate "knuckle children" (semen) onto a sandwich and then feed it to some unknowing individual.
1.) Jimmy was running his fucking mouth so I gave him a knuckle sandwich.
2.) Jimmy was running his fucking mouth so I gave him a knuckle sandwich.
You see either way its about the same. In example number one you have punched him in his mouth and example two you have made him ingest your hot and saltyjizz.
The male version of "camel toe". Where said male's pants are so tight and/or transparent, the shape/details of their anatomy are clearly visible even through the garment, resembling the appearance of a moose's lower ankle (or "knuckle").
"When I watched wrestling last night, that tag team had on spandex shorts SO tight, they were sporting some SERIOUS moose knuckle!!!"