Paddy and Mick are walking together and Paddy says "Mick, have you shit yer sel?"
"No, a have not", replies Mick.
The two tinkers keep marching down the dirt track looking for an abode when that certain whiff once again catches the nose of Paddy; "Mick, are you sure you havn't shit yer sel?"
"A have'nt shit ma sel" retorts Mick.
They reach a barn and the two decide to bed down. Mick takes down his trousers and the tell tale signs are there for Paddy to see.
"Mick, a thought you said you hadn't shit yer sel" says Paddy, as he points to the offending pile inside his pal's legs.
"Oh, a thought you meant today, Paddy!"