Of all the bizarre and colourful things British prime minister Boris Johnson has said over the years, from the Brexit bus to 'f**k business', one phrase is the most telling about how he operates. 'Convenient fiction' was the phrase Johnson used to describe how he supported the border backstop under Theresa May's government, only to reject it a few months later as a "surrender bill" and the worst possible outcome for the UK.
The game of politicians telling untruths or not giving us the full picture is as old as politics itself. But in this phrase, used by Johnson himself when interviewed in front of a live audience in Dublin last year, the British prime minister took the game to a new level.
Instead of trying not to be caught out on a lie, he came right out and said he signed up to a fiction, i.e. something he never intended to uphold as real, because it was convenient at the time.
Now, the EU negotiating team, all member states of the bloc and in particular the Irish Government are having to face the possibility of another convenient fiction.
Last time, it was his decision to support the principles behind a backstop solution to a withdrawal agreement as part of Brexit. This time, it is whether Johnson's government is viewing the actual withdrawal agreement, as it relates to Northern Ireland, as something they can "get around".
Media reports have suggested that Johnson instructed his cabinet to examine ways of getting around the need for border checks or infrastructure on goods travelling between Britain and Northern Ireland.
The agreement clearly states that Northern Ireland will remain within the EU customs union and it is inevitable that to protect the integrity of the single market and the customs union, there would need to be some kind of checks or controls, especially on goods entering Northern Ireland from Britain.
Any serious attempt to renege on this commitment, which is an international treaty ratified by the EU member states and the British parliament, would have serious repercussions for future relationships between the UK and the bloc.
Former Irish envoy to the EU, Bobby McDonagh, even suggested that such a breach of good faith could impact on the UK's ability to land a trade deal with the US.
EU chief negotiator Michel Barnier equated any question of reneging on the Northern Ireland protocol with a lack of trust which would impact on the ability to land a trade deal between the EU and the UK this year.
This sentiment was echoed by Tánaiste Simon Coveney, who appeared to say that if Johnson didn't honour the withdrawal agreement, there wouldn't be a trade deal.
Johnson may be quite capable of playing the game of convenient fictions from time to time, but the situation over the Northern Ireland protocol may not be as bad as suggested - slippery, yes, but not quite deceitful.
It may come down to a play on words. Brandon Lewis, the new British secretary to Northern Ireland, said during the week: "We always said there will not be a border down the Irish Sea; there'll be unfettered access for business."
What is a border? What does unfettered access mean? In the world of Downing Street spin, it may be important to keep up the public rhetoric and positioning ahead of the talks, only to privately acknowledge the realities during the talks themselves.
For example, there are already checks for animals crossing from Britain into Northern Ireland.
If there was a series of 'processes' and 'procedures' applied to all goods after Brexit, the British government might say it isn't what people think of when they use the word 'border'.
Unfettered access to the British market implies no restrictions, limits or tariffs on goods being sold from Northern Ireland to Britain. You could still have unfettered access to the market, while having to go through paperwork procedures and processes at the port.
Perhaps the British are looking to play with words here. There is certainly some wriggle room on both sides.
The withdrawal agreement is a specific legal deal, but there may still be room for interpretation as to the extent and nature of border checks in order to maintain the integrity of the EU market.
How often are physical checks necessary and how many? The British may be clinging to a new notion of 'magical thinking' around border solutions, but this time at ports.
If Johnson isn't just playing with posturing, PR and words, but he is actually serious about trying to wriggle out of the terms of the withdrawal agreement through obfuscation, then the UK really is in trouble.
Nobody can do business with a government that doesn't honour its international treaties.
So will there be infrastructure at ports, limited but regular checks on goods, and a detailed auditing system to ensure that goods intended specifically to remain in Northern Ireland do not actually end up in the South?
The extent of the checks that might be required will ultimately depend on the wider future trading relationship. If there is a close trading relationship between the UK and the EU, there won't be tariffs or quotas, and standards will be closely aligned. So no chlorinated chicken coming into Britain from the US in a future trade deal would mean no chlorinated chicken coming into the Republic of Ireland through an open-border back door.
There is, of course, another possibility when it comes to border infrastructure between Britain and the North. What if commitments are given about levels of scrutiny and checks, but they are not implemented to the EU's satisfaction?
If the UK said it would do certain things, and didn't, what then? Pressure from Germany, France or Spain would not carry huge weight. After all, what could they do, threaten to boot Britain out of the EU?
Under the terms of the withdrawal agreement, disputes around these issues could be referred to the European courts.
This would be a long, drawn-out process with limited scope for enforced remedies on a country that is outside the EU.
The Irish Government has to be very careful in all of this. It got what it wanted with an open border on the island of Ireland.
It must now try to get what is best for the Irish economy through the closest possible trading relationship between the EU and the UK. This will also be good for the Northern economy.
Our Government must now turn good cop after playing bad cop with the UK for the past three and a half years.
So why is the Tánaiste making public comments threatening a future EU trade deal, unless there is some kind of border placed between Britain and the North?
Surely this is a good time to step back and say very little? We have the withdrawal agreement that keeps our border open.
In the North, nationalists, who tended to be remainers, wanted to maintain an open border with the South. So did many unionists.
Neither remainers nor leavers in the North will be happy about greater procedures and processes on goods entering Northern Ireland, which will only increase costs and therefore consumer prices.
The Irish Government should let Barnier and others play tough on this one.
By very vocally entering this row, the Irish Government now sounds like it is insisting on something that pleases neither nationalists nor unionists in the North, having already secured what it wanted from the Brexit withdrawal negotiations.
The British government is due to publish its negotiating priorities today. This will fire a starting gun on what will be tortuous, high-stakes trade negotiations. With so much at stake for Ireland, it is worth realising there is a time to speak up or speak out, and there is also a time to say nothing.