A Mad Radd is performed when a person invites, calls, texts, or messages a person, when he or she knows the person is unable to attend or respond.
1.) Your chatty Kathy girlfriend calls and leaves a message saying how, "She really needs to talk about her ex boyfriend."
Instead of calling her right back, a person can pull a Mad Radd and wait until she is at work to call her and leave a message (to appear like a loyal friend).
2.) Someone you may think is boring may continually ask you to hang out. You find out that person is vacationing next weekend.. which is precisely when you ask that person to grab a drink. "Oh darn, you're out of town? Too bad....."