Short for Fag Circle Of Trust, where a bunch of naked dudes stand around in a circle and sit down on each others erect cocks and joining all that are involved in a massive gay orgy that relies on everyone to work.
Dude 1: Hey do you want a do a F-COT, we do it all the time at camp?
Dude 2: Sure.
Dude 1: Ok than take off your pants and get an erection.
Dude 2: WHAT!?!
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.