One is therefore likely to be caught up in a back and forth of "No really" "No I insist" "I insist" "But I had a pudding". And you don't know when to stop and say "All right. We'll go Dutch."
After the first offer? The second? The seventeenth?
You don't know, but I do. For I long ago adopted the Rule of the Bellman. If she offers to pay three times, she's paying. [I should make clear 1) That this only includes direct offers of payment, "But it's so expensive" does not count 2) That this is not necessarily good advice. I have seen a fair few young ladies, aghast at my acquiesence, reaching reluctantly for their purses before spitting at me and stalking out.]
I call it the Rule of the Bellman because everything I learnt about romance I learnt from The Hunting of the Snark by Lewis Carroll*
"Just the place for a Snark!" the Bellman cried,
As he landed his crew with care;
Supporting each man on the top of the tide
By a finger entwined in his hair.
"Just the place for a Snark! I have said it twice:
That alone should encourage the crew.
Just the place for a Snark! I have said it thrice:
What I tell you three times is true."
Poets are the unacknowledged legislators of mankind, just not in the way Shelley thought. It is because ofr the Bellman's Rule that three offers means a split bill.
Great men other than myself have used the Rule of the Bellman. Theodore Roosevelt told Edith Wharton:
'I am glad to welcome to the White House someone to whom I can quote The Hunting of the Snark without being asked what I mean! ... Would you believe it, no one in the administration has ever heard of Alice, much less of the Snark, and the other day, when I said to the Secretary of the Navy: "Mr Secretary, What I say three times is true", he did not recognize the allusion, and answered with an aggrieved air: "Mr President, it would never for a moment have occurred to me to impugn your veracity"!'
There's also a short story called Chaos, Co-Ordinated published in Astounding Science Fiction (1946) in which the humans manage to feed The Hunting of the Snark into the alien supercomputer as a field report and thus save the earth, largely because the computer now runs on the Rule of the Bellman and wipes its own memory of everything that it has heard only once.
But then I discovered that the rule of three was not invented by Lewis Carroll. It is far older and used to be called nolo episcopari: I don't want to be a bishop. The idea was that when somebody was appointed bishop it was a given that they would be too humble to accept the post: that's what Christian humility means. So they would say nolo episcopari meaning "I don't want to be a bishop". They were meant to say this twice as a matter of etiquette. On the third request they were meant to surrender and take the mitre. If they did not, if they said nolo episcopari a third time, it was assumed that they were telling the truth and a new candidate was sought. To say something twice may be mere manners, Truth speaks thrice.
This custom was recorded by Edward Chamberlayne (not to be confused with Charlemagne (I only mention Charlemagne because today would have been his birthday)).
Anyway, that's my rule. The rule of three, because three is beautiful. For example, observe this goal from Euro '96 where three people, including Teddy Sheringham, pass the ball across the face of the goal before making the score three nil (I only mention Teddy Sheringham only because today would have been his birthday).
Incidentally, there's a splendid blog devoted to The Hunting of the Snark which can be found here. At least I think it's splendid (I only mention me because it would have been my birthday today).
*It should perhaps be noted that Lewis Carroll never married and was probably a pederast.