Christmas is for establishment Republicans; Rand Paul celebrates Festivus.

The Kentucky senator took to Twitter on Monday morning in honor of Festivus, the holiday created by George Costanza’s father on the show Seinfeld. It was likely the first time that a sitting Senator had commemorated Festivus. The U.S. Senate Historical Office, in response to a query from The Daily Beast, was unable to find an example of Senators who had celebrated Festivus publicly in the past. Paul did not fully observe the holiday, he didn’t raise a virtual aluminum pole or engage in feats of strength, he did take part in one of the most important rituals of the day, the “airing of grievances.”

While many of Paul’s grievances were serious, including the lack of a Senate vote on his “Audit The Fed” bill and what he saw as significant increase in the debt in the most recent bipartisan budget deal, others were more lighthearted. The Kentucky senator complained about DC’s parking rules as well as what he saw as too many people on television wearing ties.

Paul didn’t celebrate the holiday alone. Towards the end of his airing of grievences, he shared what he described as “One more Festivus grievance about bipartisanship. @CoryBooker doesn't RT me enough.” That prompted Booker to join in and after the New Jersey senator offered to engage in “feats of strength,” they compromised on working together on mandatory minimum sentencing reform and federal hemp and marijuana laws instead.

But the holiday doesn’t seem to be over for Paul. He promised he’d continue sharing his concerns later in the day on Monday, saying “I still have a lot more problems with you people (Washington). I will be back later with more.”