Gay commuter (who I shall call Tom) chose a quiet moment - when the train was stationary - to regale companion with unsavoury details of his medical history.

Tom, whose real name I don't know, is renowned among the commuting fraternity for sharing details of his robust sex life with various companions and by default, the rest of carriages - since he makes no attempt to lower his booming Graham Norton-like voice.

Broad minded as I like to think I am, some of the gory details are a little hard to contend with first thing in the morning, when you haven't yet had anything to eat - or indeed last thing at night, when you've had a hard day at work.

Even his friends, with whom he chooses to share all, seem a little uneasy about it all. I've seen some of them burying their heads in papers in the hope that Tom will pass by rather than sit next to them and tell them what a fantastic night he's just had.

Yesterday I was standing a few feet away from where Tom was sitting with a friend, a can of beer in his hand and a copy of the Evening Standard on his lap, chatting about his plans for the evening with Tomasso, an Italian student he'd met in a club a few days ago.

However, friend appeared to be trying to get some work done and was largely ignoring Tom in favour of his laptop. So Tom was forced to retreat to his paper and spent the first part of the journey to Brighton digesting the latest state of the economy and the Governments plans for integrated transport.

When the train stopped outside East Croydon and all you could hear was the sound of commuters shifting in their seats, Tom decided to pipe up.

"Ohhhhhh!" he camped, "what do you know, I've had foot-and-mouth disease myself."

Friend gave him a slightly sceptical look, after all it has been well documented over the past week that an abattoir worker and couple of farmers have contracted the human form of foot-and-mouth and the only previous case ever was in 1967 - so how could Tom have slipped through the statistical net?

"Really?" he said.

"Oh yes," replied Tom, rubbing his hands in anticipation of the details he was about to impart.

"Foot-and-mouth and hand disease actually. I had it a few years back."

"What was that like then?"

"Well, apart from the name, fairly uninteresting," said Tom. "I just got a few tiny blisters in my mouth. They didn't hurt or anything but they were a bit off-putting for other people, if you know what I mean . . .

"So I went to the doctor and he said I had foot and mouth and hand disease.

"Apparently, it's caused by a virus but is not related to the foot-and-mouth disease animals get."

"Why's it called foot-and-mouth then?" asked friend, gaining a slight interest.

"Foot and mouth AND HAND," corrected Tom. "Because there were no Germans called Alzheimer or Munchausen to name it after, I suppose.

"So they simply called it foot and mouth and hand, as those were the parts of the body it affected."

"Actually," said Tom, suddenly remembering a detail that was unlike him to forget, "I'd forgotten the blisters weren't only on my mouth. There is another part of the body it affects. So really, they should call it foot and mouth and hand and bottom disease."