I got in a right pickle once asking the boss if i could borrow his car...
I walked in and said
'Can i car your borrow please Paul'
He looked at me.....
...(no sense of humour )
Nervous laughter from me.....
The trouble was it fixed in my head...it got to the stage where i virtually had to rehearse my question before i went to ask again
It REALLY was bad, i got paranoid i was going to do it again.