Chris Evans and Chris Pratt have placed a wager on the outcome of the Super Bowl.
The actors - both of whom are Marvel superheroes - have engaged in a light-hearted war of words on Twitter ahead of the game between the Seattle Seahawks and the New England Patriots on February 1, and have agreed to visit a children's hospital in costume if their team loses.
Evans, a Patriots fan who plays Captain America, said: "Well, well, well @prattprattpratt, looks like our teams are going into battle. For the next 2 weeks, you are not my friend, you are my enemy (sic)"
Pratt, a Seahawks fan who plays Star-Lord, replied: "We both know there's only one Captain America and his name is Russell Wilson."
Evans responded by asking his fellow actor whether he wished to place a bet on the outcome of the big game.
Pratt responded: "OK. Seahawks win you fly yourself to Seattle, visit @seattlechildren hospital as Captain America, waving the 12th man flag."
Evans accepted the challenge, predicting his team would win the Vince Lombardi Trophy.
He said: "I accept. And when the Patriots humiliate your seachickens, I expect Star-Lord to arrive at @chris_haven in a Brady jersey."