The meal was quite nice, for a quick pre-theatre bite – goat's cheese salad, salmon, crème brûlée – the usual, in short. With the house wine, a £12 deal has mysteriously turned into £25, but the right food was handed in the right order to the right people at the right intervals.
So what to do about that "optional" service charge? Pay up, or stick to principles that may inform momentous social change come the next government or three, but that won't cover this nice young woman's bus fare home?
You haven't paid extra for the gas that crisped the fish skin. You haven't paid a surcharge for last spring's paint job. Or for the lights being on. But this particular running cost, that of paying the staff, has been bundled on to the customer like a box of curios from your parents' attic – unwanted, unlikeable, yet heavily laden with a sense of obligation.
You didn't tip the sales staff when you bought the dress you are wearing, the driver of the train that got you here or the box-office manager who printed your ticket.
Time to make a stand, and force restaurateurs to pay their staff at least a living wage. For too long they have taken advantage of diners' reluctance to start the "Does this money go straight to you?" conversation in front of friends eight minutes before curtain-up while waiting for £3.20 change.
And yet… if it was your child on her feet all evening, heaving bowls of gruel and refilling carafes of tap water for minimum wage, wouldn't you want more for her? Let's call it a tenner. But next time…