It's bad enough being lectured by politicians from Edinburgh or even London. That, I suppose, is to be expected however. Irritating but normal. It's rather different when foreigners - real foreigners - decide to interfere in our own constitutional rammy. It smacks of impertinence.
When that intervention comes from the leader - to put it in Sun-speak - of a nation of donkey-slaying, rock-coveting bankrupts it's even less respectable. So the suggestion made yesterday by Mariano Rajoy, Prime Minister of what we still call Spain, that an independent Scotland would, by creating a new country, need to reapply for EU membership is hackle-raising stuff.
You're tempted to reply jog on, pal.
Of course Rajoy's remarks are not about Scotland at all. They are about Catalonia. Like most people in this country I am supremely indifferent to Catalan independence. They can do what they like and it is no concern of mine. Or yours. I doubt we will see or hear David Cameron or Alex Salmond expressing an opinion on the matter and that's as it should be. You might hope Senor Rajoy would act with comparable restraint when considering Britain's own internal affairs.
It is true, of course, that Scottish - or Catalan - independence would be a new kind of thing taking the EU into unchartered waters. No-one has previously seceded from an EU-member state. And so, as Alistair Darling is keen to stress, there is inevitably some uncertainty here. This is an undingable chiel and it is silly to pretend otherwise.
Nevertheless and be that as it may, it also seems clear that new states such as Scotland or Catalonia are in a rather different position to that enjoyed - or endured - by states outwith the EU applying for admission. It follows that accession would have to be treated differently too.
The process for admitting Scotland or Catalonia would doubtless require some delicate negotiation and there might be a need for some transitional arrangements but nothing nearly so complex or time-consuming as admitting wholly new member states such as Croatia.
The reality - another known unknown, admittedly - likely lies somewhere between Rajoy's dire warnings and Salmond's cheery, even breezy, assumptions. (Those assumptions, mind you, are too often too cheery. It seems most improbable that Scotland can get everything it wants without compromising on anything at all. Anywhere.)
Meanwhile, I understand the temptation for Unionists to use Rajoy's remarks as a "See, told you you so" stick with which to poke the nationalists. But this too is something to be handled delicately less it blow up and damage their own cause. Endorsing Spain's analysis risks coming across as opportunistic; endorsing it with evident gusto and relish is mildly unseemly. Not least because should Scots actually back independence (almost) all Unionists will then support the SNP's present position and argue that Scotland's EU-accession be as quick and seamless a process as possible. Given the choice between Spain and Scotland they will, I trust, choose Scotland.
So, yes, there is some uncertainty. But many things are uncertain. Uncertainty is always with us. But uncertainty alone is not - or should not be - enough to decide the issue. Better instead to argue from first principles and win the argument on that basis, not on the back of dire warnings that you cannae do that because it will annoy the Spaniards. I mean, really.