Prince Harry claimed that his brother Prince William and sister-in-law Kate Middleton urged him to wear the Nazi uniform he infamously donned for a 2005 costume party and howled with laughter when they saw him dressed up.

The accusation is reportedly detailed in Harrys upcoming memoir, Spare, according to Page Six. Harry wrote that he couldnt decide between a normal pilot uniform and that of a Nazi, the outlet reported, leading the young prince to call his brother for help.

I phoned Willy and Kate, asked what they thought. Nazi uniform, they said, wrote Harry.

When he tried on the uniform for them, he wrote, They both howled. Worse than Willys leotard outfit! Way more ridiculous! Which, again, was the point.

Harry was 20 when he attended the Native and Colonial-themed costume party. Tabloid photos showed him with a red swastika-emblazoned armband on his biceps. His brother was dressed as a lion.

I felt so ashamed afterwards, Harry said in Netflixs Harry & Meghan documentary series, which premiered in December.

All I wanted to do was make it right, he continued. I sat down and spoke to the chief rabbi in London, which had a profound impact on me. I went to Berlin and spoke to a Holocaust survivor.