The Honeycomb & The Jackass
Now, for a third and final time, we have been teased with Tyrion's 'honeycomb and jackass' joke, only to have the punchline stolen away from us…even in the GoT finale…
Starting in season one, Tyrion first attempted to tell his joke when he was a captive of Lysa Arryn and Catelyn Stark, on trial for his supposed role in the attempted murder of Bran Stark.
It would be five seasons later before we heard Tyrion make a second attempt at telling his joke, this time with Missandei and Grey Worm in Meereen.
On the first occasion Tyrion gets cut off by Lysa Arryn, and the second, he is cut off by an impending attack by the Masters.
Since the second attempt, there have been several attempts to guess the joke, and many have speculated that the joke has some deep, hidden meaning to upset the whole series.
While it is probably rational enough to suspect that an unanswered story like this in Westeros would have an important message, more sense would go to this simply being a fun Tyrion-ism that's wound its way through the series.
Posted to the Game of Thrones Reddit page, user Retro21 may have just found the answer.
Obviously, this is unconfirmed, but it is so perfect that we'd be shocked to find this wasn't the punchline, whenever we hear the end in the series.