Reverse Jiffy Lube 

A hybrid of the popular reach around penis grab. This occurs when a female reaches between a males legs from behind and begins to grip and rub the penis. Done over clothes and results in a penis erection. Usually done as a mating ritual to see if the male "sizes up" so to speak.

Jenny is giving Earl a reverse Jiffy Lube. That lucky S.O.B.

Reverse Jiffy Lube by DIRECTOR DRE December 9, 2008

reverse jiffy lube 

A maneuver in which a female reaches between a man's legs from behind in a attempt to cup a feel of said man's cock. This is an attempt to see if the man "measures up" to her standards.

Michelle: "Jewel has reverse jiffy lubed almost every guy at the bar. Seems like only Rod fit the bill."

Sandy: "What a whore"

reverse jiffy lube by Dre the Director December 20, 2008