So lately I've been seeing the word side chick thrown around a lot (same with side dude, or whatever) what exactly is this? I understand the general premise obviously, but do these side girls know that they are a "side girl" or are they being lied to? I guess my question is for ladies (guys too) could you be a "side" person for someone that's in a relationship? I don't think I know a single girl that would willingly go about this, but apparently it's becoming more common.