The act of implying that you have a significant other, but refusing to fully commit to being in a relationship by saying you are taken. Also used to confuse people who are very drunk into thinking you are available for drunk-sex when your significant other is standing near or is in the same room.
"So, wanna go back to my place?"
"Well, I'm not-single, so...."
"....Alright, so wanna go back to my place?"