The act of eating a sandwich, getting a blowjob, and taking a dump all at the same time.
Jesse -"Why weren't you in class"
Rich - "Sorry I was busy getting a blumpkwich"
Jesse - "..."
The act of getting a blowjob by two girls while eating a sandwich and taking a dump.
Jesse - "Why weren't you in class again?"
Rich- "I was getting a double decker blumpkwich."
Jesse - "I dont know whether to be jealous or throw up."
Rich- "Your just jealous."