A Dirty Three is a term used to describe the action of vomiting, defecating and urinating oneself.
This may occur for a many number of reasons, and can be an inconvenience.
'Mate, I'm not gonna' lie, I totally did a dirty-threer in The Black Swan toilets last night.'
OR
'Uh oh, I feel a dirty three coming on...'
A pony tail worn by a man (usually a hipster).
Wow look how long his monytail is!