When a blowjob is cut short, and ends in the unfortunate situation of blueballs.
She was blowing me pretty good, but got lockjaw when I was about to cum. Turned a great blowjob into a lousy bluejob.
Any kind of blowjob that involves the use of blue food coloring.
"Do you do fetish? 'Cause I got this big thing for the color blue..."
"You mean like a bluejob? It'll cost extra."