Why? Why do people do this?

It's a pet peeve of mine, and I've long since got used to fact that by the time you're standing outside the building the group part of the evening has ended. If I'm on my own I'll shout a cheery goodbye and be on my way, but The Light feels awkward doing that while others are still shuffling their feet on the pavement so we will stay until everyone else realises that it's time to go home.

Sometimes it's best to just slip away. I like the dog in the fog route.

Only works in large crowds though.

But my girlfriend thinks it's rude, so when on my own I do the sneak off and when with her I stand around like a lemon and wait to say goodye to each and everyone in the room.

That after the cleaner wakes me up hoovering round me on the pub carpet, she's not really bothered whether I say goodbye or not.

In Spain, the dog in the fog is known as leaving a la francesa, for reasons no doubt best known to some French person who once buggered off without so much as a by-your-leave.

The tactics have changed recently. Before the smoking ban, you could always nip outside a fug-laden club muttering something about "a quick breath of fresh air", never to return. Now the opposite applies: you claim you're going out for a quick smoke, never to return. The only flaw in this plan is that everyone then looks at each other and says, "But he doesn't smoke - he's obviously leaving a la francesa."

Mobile phones also offer a relatively new out that can come in handy in noisy places, consisting of holding up your phone to the Assembled Throng (tip: for optimal verisimilitude, press some button at random first so the screen lights up), looking very apologetic, holding the thing to your ear, shouting "Hang on, I can't hear you in here with all this racket," and striding off the premises, never to return. If the Assembled Throng are so drunk that there's a risk they might not register any of your carefully prepared pantomime, you might need to preface this action by making a series of spasmodic hip movements to simulate the vib-mode ringing of the phone in your pocket. (Just imagine you're being Tasered with one foot in the bath and the Assembled Throng should get the idea. Unless they've been drinking tequila, in which case you have no need to worry about leaving; they won't even remember you were ever there.)

on how much leeway I've left myself between last trains/night buses or how many small sherries have been consumed.

Kate Fox was quite erudite on the subject of the English and our inability to leave anywhere easily in her book Watching The English.

A quick search also lead me to this
http://english.stackexchange.com/questions/30115/is-there-an-english-phr...

I just bugger off. Always have. My friends used to nickname me the phantom.

saying goodbye, handing out hugs, handshakes and manly shoulder-punches as appropriate, making 'I'll call you' hand signals as I reluctantly withdraw, declaring undying friendship to people I met an hour earlier and saying 'we really must do this again' at least thirty of forty times.

Not really. I get flustered by the formalities of farewells - who gets a kiss, and is it kiss&hug, mwah kiss, both cheeks? I hug my close mates, but if there's someone I know a bit less well with us, can you go hug, hug, handshake, hug? It would be a minefield even if you were sober.

So I slink out even more inconspicuously than the Dog in the Fog. I'm the Mog in the Smog.

that I've been adopting the Dog in the Fog routine all these years,without knowing it had a name. *slinks away silently, tail betwen legs*

And hang around like the aforementioned 'Lemon'.

I have a friend however who's departing gift is as follows. You turn around and know he's on the way home because that's his bottle spinning in circles on the bar.

Another who actually has a fog come down on his eyes and becomes another person completely. He walks out past everyone as if he has never met them in his life and says nothing at all. He remembers nothing. Just that he must get home. We just pray he makes it in one piece. He does. So Far

...everyone I can see who I've spoken to over the course of the evening might get a handshake and an effusive farewell. If I can't quite get over them, they'll probably get an "Oi, X!" accompanied by a Macca thumbs up and a chinny grin.

If I'm sober, I'll probably back out when no-ome's looking.

as it's known in my corner of North London.

That's when I announce my intention to leave, but am still there a good hour later, still saying my farewells.

Mrs L, however, takes bloody ages, having to have lengthy bloody conversations with bloody everyone about bloody everything before finally bloody departing.

You can tell that this doesn't irk me at all.

Gotta rush - last train....

Works a treat.

At whichever Mingle they next go to, is going to wind themselves up tremendously when it gets close to chucking-out time!

so I don't think they miss me when I'm gone

I believe the art is mastering an air of anonymity.

However, depending on my mood and level of inebriation, a more apt analogy could be a lump of stale chewing gum woven into the Wilton.