The inability of the female human to simply STFU. It is a gender specific disorder that strikes 100% of women, yet the sufferers of YVS are 100% male. Symptoms are deep single breaths in between strings of words and the afflicted men replying in grunts. Aha, um hmm and yes - no replies are all that is possible because the men cannot get a word in.
Does Kate EVER STFU? Naaaah, man. She's gotYappy Vagina Syndrome.
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?"