When I was about 15, my 10 year old cousin stood up in a restaurant to go to the toilet, and my grandma, who'd had a sherry too many, called after him, "is it a poo, Christopher?"
He just said, "earth, swallow me now," and walked off.
Also DP has a real thing about buying toilet rolls. He hates it - says "everyone knows what you're about to do." I tell him he's being ridiculous and nobody would notice or care.
Then when DD was a tiny newborn, I made him pop to the local shop one night to buy some toilet roll as we'd run out. He didn't feel the need to pay 5p for a bag. Carrying it home, a car goes past him, the window goes down, and a lad calls out...
"HAVE A NICE SHIT, MATE!!!"
I have still not been forgiven.