What is Doing A John?
1.
Lusting after a young girl with the intention of postponing a sexual proposition for an undetermined number of years.
Often the perpetrator will announce the number of years he intends to wait in a grumbled tone.
So my little sister just started junior school. Yeah, she is doing really well, better than I was at that age. Hey John, I won't be in lesson because I've got to go and pick her up at three.
Four more years...
2.
Entering a public toilet and using the facilities improperly; often involves leaving faeces in the toilet bowl without initiating the flush mechanism.
"See that bloke over there, the one with a newspaper, he is doing a John."
"Dirty bastard"
3.
to unexplainably lose all your money in five hands of poker
'Damnit five hands and im all out!'
'shut yo jibba jabber and stop doing a john!'
*crys then begins to masterbate*
See