Already, we've spotted some on-stage nuttiness, so to speak, as Liam punched Harry in the...well...balls.
Oh yeah, he went there.
Harry also gave Niall a nipple burn and check out the gif below to see Liam faking out Louis with a high five.
We imagine all these little pranks and mischief keeps things interesting while they're touring, but remember to play nice, boys.
Niall suffered the nipple twist when his shirt shifted, giving Harry an opportunity to grab while Niall played guitar. Poor guy!
Harry, evidently was on the receiving end of nipple-twist karma, when Liam got in a shot right in Harry's baby maker (captured on video, for your viewing pleasure).
Something tells us we'll be seeing many more pranks and general naughtiness during this tour!