Here's one I've been telling for twenty years - still love it:
Old Lord in the bath - rings the bell and in comes his Butler, Waddle
Lord: "Can you get me a whisky please Waddle?"
Waddle leaves- comes back with a whisky
The Lord rings the bell again, and in comes Waddle
Lord: "Can you get me a cigar please Waddle?"
Waddle leaves- comes back with a cigar
As Waddle leaves the bathroom the Lord lets out a loud underwater fart.
5 mins later Waddle comes back in with a hot water bottle
The old Lord says "Why have you brought that?"
Waddle says "Well as I was leaving I distinctly heard you say "what about a water bottle Waddle"
Works best if you say the last bit very fast