When you're getting it on with a girl and she all of the sudden dries up, you have to quickly eat her out for awhile to get her wet again before you lose your hard on.
When she dried up during sex, I had to give her a jiffylube to keep it going.
Fret lube is using the oil from your forehead or nose to lube up the buttons on a guitar hero/rock band guitar for faster playing.
Rock Band Player 1: Damn, I can't hit that green/red to blue/orange transition.
Rock Band Player 2: Dude, use some fret lube on that shit and shred it up!