'Slopdog' is a sloppy poo, common after a big night 'on the piss' (drinking alcohol).
See also 'grog bog' or 'runny bum'
Azza - "Aw, mate... I just checked your snapchat and that was fucking disgusting."
Bazza - "Oath, mate. Had a big night on the tinnies, mate, I had some slop fall out of me aye, it was actually a bit of a 'slopdog'."
Azza - "It really was. My mother got it too, you're a cunt."
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?"