Stealing, cheating,crashing on bikes, lying, asking for bowls of cereal upon entering someone's house and trying it on with girls that have boyfriends...
Example 1 of Doing an Ash
Bob: Hey Olly can I meet your girlfriend uptown today?
Olly: No stop being an Ash!
Bob: Hey olly can have a bowl of cereal ?, and oh btw I met your girlfriend uptown even though I said I wouldn't.
Mike: Man Bob jus properly triple Ash'd you there!