A random person that suddenly appears next to you, in order to arrange a situation that seems more intimate than that of a stranger. Usually used during ARG games for photo-op points, or as a strategy to divert your opponent's attention.
Jane: Hey, I saw you talking to that cute Asian girl yesterday, you two seemed pretty close. Is she your new girlfriend?
John: Hell no! That was a framefriend! She marked me as soon as she got on the bus. When she made her move pretending to be lost and asking me to bring her to her destination, I immediately exited the bus and power walked her there…9 blocks away....uphill....in the rain....with her high heels on….