Given the animosity between George Osborne and Ed Balls it is sometimes surprising they can sit in the same room together without getting into a fight - let alone babysit each other's children.
However on Sunday morning the chancellor offered to look after his Labour rival's son for half an hour while Balls went on BBC Radio 5 Live.
The cross-party childcare assistance happened after the pair had both appeared on BBC One's Marr show earlier in the day to trash each other's economic message.
Osborne's decision to step in as a nanny was revealed by the political editor of the Financial Times, George Parker, who tweeted on Sunday: "Heart warming scoop: George Osborne looked after Ed Balls's son Joe in BBC Marr green room this am while Ed did R5 @JPonpolitics interview."
The story was later confirmed to The Times by spokesmen for Balls and Osborne.
Balls and his wife, shadow home secretary Yvette Cooper, have one son and two daughters. Osborne has one son and one daughter. Both men have been keen to keep their children out of the public spotlight.
Balls also does his bit to look after the kids of Westminster - he plays the part of Father Christmas every year at parliamentary Christmas party.