An embarrassing thing all around...
S & D were at the coffeehouse. One of D's old friends came in, got a coffee drink, and as he was leaving, D saw him take a pastry and sheild it from view as he left.
Since D knew him, he gave S the phone number for his parents, with whom he lives.
S called & left a very polite message about could he please come pay for the pastry, because in order to buy some for tomorrow we need to make money on the ones we have today.
Later...
The friend calls back, obviously embarrassed, and explains to S that the pastry was the half-eaten one someone had put in the bus tray.
Ouch.
S was glad he had been so polite in his message.
Live and learn.