I mixture of the Scottish slang word 'mugged' meaning drunk, and 'muggle' the word for non-magic folk in Harry Potter. This is the ultimate Harry Potter fans's way of saying drunk.
'I was totally muggled on Saturday night! I drewglasses on myself in permanent marker and tried to fly on Katie's mop!'
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.