Disclaimer: Not mine.
The first time was when looking at Daemon's pocket watch. Giotto had realized that instead of the words which they have all engraved on to their watches, was a picture.
A picture of the family, but more importantly, a picture with her.
She was Daemon's lover.
The second time was when Giotto had made a mistake. A mistake that cost more than his pride. The pride of the family. And of course, the life of Elena.
After that, we all watched as Daemon threw his life away to fulfill some silly promise. The love he had for Vongola versus the love he had for Elena. Of course, he embodied what Elena had said about protecting the weak along with Vongola. Though he had misunderstood, and as a result the guardians paid the price.
The last time was when Daemon had finally broke the bond between the mist and the sky. After all he had finally lost his sanity. Betraying the famiglia and as a result, the Shimon famiglia took our responsibilities and disappeared, without a trace, from the world.
With three strikes, the batter is out. Daemon had finally broken the last sliver holding the thread that threatens to break. At exactly 12:04, the bond was truly broken.
The vow between us no more.
Givro eterna amicizia.
Ten generations later after witnessing Decimo's resolve, Giotto met up with Daemon once again. For the last time, and instead of the picture on the top lid, was the vow that all the guardian's and the boss had made several years ago.
Maybe, just maybe, that bond has not been broken as of yet.