The combination of the words Shenanigans and Antics.
When something is so crazy, so F-ed up, or so stupid that it is used with the word "Shenantics", the two combined words instead.
Besides, no one really used the word "Shenanigans" seriously unless your'e over 40.
1.
Mark: "F*ck Nick, I am SICK of your SHENANTICS!!!"
2.
Lacey: "I just want to get wasted tonight.."
Jenny: "TIME FOR...."
Lacey: "SHENANTICS!"
3.
You: "The a-hole buss driver saw me here but didn't stop.." :(
Me: "F*ckin' shenantics man!"
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?"