WATCH: Cory Booker loses to Jeff Flake in snowball duel on Capitol Hill

US Sen. Cory Booker will be buying fellow senator Jeff Flake's staff pizza after the New Jersey Democrat lost a snowball battle to the Arizona Republican on Thursday.

"I neglected to tell him though that I am definitely sending a vegan pizza or two," Booker, a well-known vegan, said on Twitter.

Booker and Flake both called the snowball fight a duel, with Booker citing the famous Alexander Hamilton-Aaron Burr duel. Whoever got hit the most would buy pizza for the other's staff, Booker tweeted. Booker later conceded, saying he lost the battle 3-2.

Booker, though, said he was set up, tweeting, "Lost this morning's snowball duel to a guy named Flake from Snowflake, Arizona!"