Well, interism is what some teenagers or kids refer to as a religion that revolves around the online region the name comes from 'internet'. You will probably never hear your parents or adults say anything about this certain 'religion' UNLESS they are some sort of youtuber or are in to the lives and interests of mainly teenage girls.
The only religion that a person should follow
it is the religion of Yatesiboy who is literally jesus himself and will cheff you up if you dont bring him sacrifices every full moon
the sacrifices are the naked Ethiopian child which he eats.
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.
FRIEND A: "Did you just take a stealthie of me?"
FRIEND B (turning phone around): "no I was just using snapchat's new filter, see?"