Two ex squaddies had left the army and hit hard times, both ended up as down and outs sitting on a bench drinking meths and cider.
John turned to his mate and said "Theres a fucking awful smell round here have you shit yourself?"
"No!", said Jack.
After a few more bottles Johns nose was twitching again and he said "Are you sure you havent shit yourself?!"
"Of course I'm fucking sure!", said Jack.
Anyhow both now well pissed they went to the Sally army to find a bed for the night. When they went for a shower John noticed that Jacks underpants were caked with shit.
"I thought you said you hadnt shit yourself!"
"Sorry", said Jack, "I thought you meant today."