If a swanky bar guarantees to "take the drinker on a journey of discovery", I'm going to walk in, order something with a pretentious name and wait for something to happen. A young, slim, smooth-skinned couple on a date sashayed in five minutes after me and sat at the adjoining table; they coyly played with their hair, laughed self-consciously and mentally marked each other out of 10 for grace, charm and likelihood of being a serial bigamist.

After a while the guy excused himself politely to visit the bathroom.

But on returning, in a staggering breach of dating protocol, he put his index finger under her nose and said "smell this". She had little choice but to comply; she instinctively recoiled, but not far enough to avoid the aroma of his finger. If his grand strategic plan was to get her to smell his finger, he'd just played a blinder.

He'd triumphed. But at what cost? Commanding people to smell things is no way to ingratiate yourself. The only situation where it might be acceptable is during some kind of party game where pairs of contestants have to guess odours, blindfolded, against the clock, which I don't think even exists but could conceivably enliven a dull Boxing Day.

But this was a date. Imploring your date to smell your finger, or pull your finger, or do pretty much anything with your finger, is an inadvisable act of romantic sabotage. Romeo was very careful not to tell Juliet to smell his finger. Wedding vows, even modern ones, don't include a promise to regularly smell each other's fingers for evermore. Eric Clapton's hastily scribbled first version of the song Wonderful Tonight did not read: "We go to a party and everyone turns to see / this beautiful lady that's walking around with me / And then she asks me, 'Do you feel all right?' / And I say, 'Smell my finger'."

So next time you're on a date and you go to the bathroom and find some gorgeously scented soap in the dispenser, and you come away with the delicate perfume of almond or rosehip on your hands, don't return and thrust your fingers into the face of your blameless companion. Say, "they have rather nice soap here, you know," then segue into a conversation topic chosen from my best-selling pamphlet, Mildly Excruciating Dating Chat for the Socially Awkward.