In the day MP Boris Johnson confessed to Oxford Mail readers that he had once taken cocaine, I had a three-scoop ice cream cone - rhubarb crumble, raspberry cream, and rum and raisin. It was a lapse soon to be regretted. But the temptation had been overwhelming. The pusher - or rather the bright-faced young woman behind Thornton's cold cabinet in the Westgate Centre - had allowed me to sample all three. The promise of a caramel stick to accompany the trio of calorie-crammed creams was the clincher. The door into Queen Street was still yards away when a small child pointed at the towering cone and asked his minder, possibly his grandmother, for something similar.

"That's too big - and it's greedy," she said loudly, firing a disapproving glance. By the time I reached County Hall, the ice cream was dripping like a tap. Stemming the rivulets of the chocolate-capped cone was impossible. The situation was made worse by the appearance of a friend; she works in that cauldron of administrative power. Chums we are, but she is not the sort of lady you invite to share a cone, nor in whose company you would feel comfortable continuing to lick.

By the time we parted, the melting ice cream was a raging torrent. At Nuffield College, the rum and raisin had collapsed, with a couple of the latter stuck to the cap of my right shoe. A group of young teenagers found amusement in seeing ice cream on the nose and chin of someone of riper years.

What should have been a pleasure was a disaster. But then I thought of Boris. I would have no need to explain my indiscretion to a constituency party, nor risk a verbal lashing from an Old Etonian chum, his Witney-based Tory leader. The worst likely outcome was a dry cleaning bill for my regimental tie that had sustained fallout damage.

Gin and tonic it had experienced, with the occasional soaking from a brandy and soda, but rum and raisin was a combination too far.

Cornmarket Street was ablaze with colour and noise. It is unlikely the Tower of Babel experienced more languages on a busy day.

But this confusion of tongues could not drown out the violinist beneath the tower of St Michael at the Northgate as she played a haunting melody set to that WB Yeats' poem, Down by the Salley Gardens, nor the foot-stamping and clan-stirring performance of an inappropriately dressed bagpiper clad in dark grey T-shirt, shorts and boots outside HSBC Bank at Carfax.

The glorious weather added to the pleasure. Tossing a few bob their way seemed insufficient reward. Yet on a dull, wet day, the music would have been an intrusion and the multi-lingual crowd a darned nuisance.

The three American tourists were fascinated by the French-influenced sandwich bar and café in the Covered Market.

The extensive menu was to their liking, although they were anxious about the nut content for their allergy-prone son. At their invitation, I recommended the salmon combination, only to be told junior was likely to have a reaction from fish, while the cheese combinations were sure to upset his dairy-delicate stomach. Her husband had to be careful with pastrami, while all three avoided eggs, just in case salmonella was lurking.

How long were they staying in Oxford, I asked, trying to think of some hypochondriac-friendly eatery where they could dine later without fear. Her reply consigned this plan to the waste bin.

"A couple of hours. Maybe you can headline some must-see places while we're in town?" she inquired in a Texan drawl, inflicting damage on the English language as only an American can do. In view of their delicate digestive systems and the brevity of their stay, the A&E department at the John Radcliffe sprang to mind.

But this was resisted in deference to the special relationship' between our nations.