The 19-year-old singer locked lips with funny-man James all in the name of entertainment after the British boyband appeared as guests on the Sky1 comedy panel show.
Harry and James took it all in their stride as they passionately embraced, with Harry sitting on James' knee and tenderly holding his face!
The good friends attempted to reenact a 'Kiss Cam' moment, similar to the impromptu on-screen kisses that take place during US sporting games.
Harry, who recently won two Teen Choice Awards for Choice Hottie and Choice Smile, then shared a chuckle with James as he pulled away.
Harry wasn't the only one to take on a dare, as his band mate Niall Horan also got in on the action by getting a tattoo of James' face transferred onto his bottom!
A League Of Their Own, hosted by James with regular team captains Jamie Redknapp and Freddie Flintoff, alongside comic Jack Whitehall, returns to Sky1 on 23 August.
The episode with One Direction is set to air 30 August.