Definitions by Resting peace

If you know, you know 

The defining phrase of an inside joke/access to information only a select few know about

You see your mate's laptop screen saver is a naked girl, but her face is covered , you know who it is, but others don't- you post it on your snapchat and put "....'s screensaver, if you know, you know"

If you know, you know by Resting peace October 11, 2015