Hop off my johnson means in a different phrase "get off my case". Used mostly when youre just joking around with your friends but can also be used when trying to get someone thats attempting (and probably failing harshly) to tell you off. They get confused, you walk out feeling good that you got away from that.
Person 1: "I bet you've never even been kissed before, have you?"
Person 2: "Hop off my johnson!"
*person 2 walks out while person 1 is still in a state of confusion.
Person 2: "Hop off my johnson!"
*person 2 walks out while person 1 is still in a state of confusion.
by SceneSuxBalls kthnxbai! June 8, 2010
Synonymous with "hop off my dick". A phrase primarily used to tell someone to "stop sucking up to me".
Hannah: Josh, you are so smart and attractive.
Josh: Hop off my Johnson!
*Hannah begins crying and runs away embarrassed*
Josh: Hop off my Johnson!
*Hannah begins crying and runs away embarrassed*
by Laffs November 14, 2011