Having recently finished watching The Army Game, and presently watching the spin-off Bootsie and Snudge, I can just imagine Bill Fraser's CSM Claude Snudge saying these lines..................
From Clement and La Frenais biogs. "More Than Likely" that I am reading at the moment.
It's not often I burst out laughing when reading - the first line grabbed me, but this is one step up from "Am I hurting you by standing on your hair":-
Ian is in town and is spotted by an RSM, who beckons him over, and as he looks Ian up from his unpolished boots to his cap badge, he says...................
RSM "What are you?" 
Ian "Er, um, not sure Sarnt Major"
RSM "Shall I tell you?"
Ian "Yes, Sarnt Major"
RSM "You are a mobile shithouse"
BEAT
RSM "What are you?"
Ian "I am a mobile shithouse, sir"
LOVE IT 