On Thursday evening, EU heads of state gathered for dinner in the European capital after hearing Theresa May lay out her government's "generous offer" for citizens from the bloc living in the UK. In an embarrassing move, the British prime minister was reportedly required to leave the room for 10 minutes so that the other 27 leaders could discuss matters relating to Brexit. German Chancellor Angela Merkel, hopeful as ever, spoke of a "good start," while European Council President Donald Tusk simply called the offer "unsatisfactory."

Read more: Skepticism in Brussels over the UK's post-Brexit promise for EU citizens

The details

May laid out her 15-point plan in London last week, in which she elaborated on who would be allowed to maintain their rights in the UK following Brexit.

"No one who's illegal will have to leave the country," is the guiding principle of the plan. But when it comes to complicated legal disputes, the devil is in the details, and May's proposal is already drawing the ire of some in Brussels. Only those who earn more than 18,600 pounds ($23,800, 21,000 euros) are allowed to bring a foreign spouse to the UK, for example. And all foreign nationals will be required to register for a new residence document, something that would be considered a rights violation for British citizens for whom the rule doesn't apply. It would also be unequal treatment to allow Irish citizens to keep their right of residence. And so on.

The timeline for these proposals to be enacted is also a bit murky. The EU has taken a clear stance on the matter: Until the UK officially leaves the EU on March 29, 2019, citizens will be able to maintain the full scope of their European rights, including freedom of movement. But the British proposal sets March 29 of this year - the day Article 50 was triggered - or another possible date as the deadline. This isn't likely to happen.

And finally there's the dispute over the European Court of Justice: Legal enforcement will be overseen by the "internationally recognized British courts," according to May. For her, this point is non-negotiable because of the matter of British sovereignty. What else would Brexit leave the UK?

The EU on the other hand continues to see the European Court of Justice in Luxembourg as the legitimate court. Only a compromise - something like a supra-national arbitration - could help on this matter.

It's all incredibly complicated

All in all, there's still a lot that needs to be negotiated. And the reaction from Brussels was correspondingly cool. "A number of the limitations [in the proposal] make me worried," said the European Parliament's chief Brexit diplomat Guy Verhofstadt. He sees the promised simplification of administrative procedures as a positive development - but other details need to be more closely examined.

Michel Barnier, the EU's chief Brexit negotiator, reiterated that Brussels' goal was to guarantee EU citizens the same rights as before in the wake of Brexit. "We need more ambition, clarity and guarantees," he said. In other words, he considers the proposal so far to be inadequate.

What is already clear at this point in the negotiations is that it's all incredibly complicated. Every detail of the gradually entangled rights of EU citizens must now be reviewed. As the Financial Times reported in a heroic investigation, 759 international agreements involving the EU must now be renegotiated. Have fun with that. Especially in London's understaffed Brexit office.

Outbursts of patriotism

The fact that nerves are fraying in London following the failed parliamentary elections is not surprising. But some government officials are completely losing it. During an interview with BBC moderator Emily Maitlis, prominent Brexit campaigner and Leader of the House of Commons Andrea Leadsom was overcome with a sudden rush of patriotism. Asked about the challenges faced during the first Brexit negotiations, Leadsom said: "It would be helpful if broadcasters were willing to be a bit patriotic."

Leadsom, who was considered for prime minister last summer, apparently failed to recognize that "patriotic journalism" is also known by another name: propaganda.

Is it love?

Brexit Minister David Davis meanwhile suddenly discovered his admiration for EU counterpart Michel Barnier. "He's very French, very logical, very dignified, very elegant," gushed the Briton in a Sunday interview with the BBC.

That French charm must have hit Davis like a lightning bolt. But what chance does their burgeoning bromance have as the negotiations move forward? At the first pull of the trigger by one of the two delegations, their affair will likely end with a broken heart.