A form of blow job when the giver munches or chews, it can be intended or by accident, depending on the context it's used in.
Pmsl, Jeff told me Shirley slipped when she was tasting his meat, gave him a munch job.
Damn, that Laura girl's one kinky slut, gave Jonny a munch job yesterday.
Someone whos head (the one with the brain) is full of smeg.
Smeg is the nasty stuff under one's foreskin after not washing it for too long. This word is thusly often used in insults.
- Hush your noise smeghead!
- That guy's a right smeghead...