On the night of Halloween 2012, Liam, Zayn and Louis went out, while Harry and Niall stayed at the hotel.
Zayn and Louis, had their faces covered in white makeup/facepaint.
The next day, in an interview, you could still clearly see make up on Zayn, and on Louis. But if you look closely in Harry's hair, you can clearly, obviously see white make up.
But Harry, I thought you stayed at the hotel??
Unless, the makeup came from Louis, or Zayn, but this is a Larry evidence book, not Zarry evidence.
Watch the video, Link in comment if video isn't on the side and see for yourself.
Picture of Harry's hair on the side...