I do not know.

"Who's in charge around here?" "Don't ask me. How would I know?"

He stole his neighbor's underwear once. Don't ask me why.

Related vocabulary: go figure

• when something sneezes, someone catches a cold
• when something sneezes, something catches a cold
• When the cat's away .
• When the cat's away the mice will play.
• when the chips are down
• when the dust settles
• when the going gets rough
• when the going gets tough
• when the spirit moves
• when the spirit moves you
• when was a mere twinkle in father's eye
• when was a mere twinkle in their father's eye
• when was a twinkle in father's eye
• when was a twinkle in their father's eye
• when your ship comes in
• where is coming from
• where someone is coming from
• Where's the beef?
• Where there's a will there's a way!
• Where there's muck, there's brass.
• where there's smoke, there's fire
• whet appetite
• whether by accident or design
• whether or not
• whet someone's appetite