Prince William was at the embassy to sign a book of condolences for the victims of the shooting at Orlando's gay nightclub Pulse, which happened on Sunday. Afterwards he and the Duchess spoke with staff who have worked on LGBT issues, and during the meeting he mentioned his upcoming magazine appearance.
Prince William revealed he is to appear in gay magazine Attitude
Craig Petty, president of LGBT association GLIFAA, said: "I told him what I do and he said he's going to be in Attitude magazine. I was really nervous about meeting the royal couple but they are both great at putting you at ease. I think it's great they have come here today to show their support."
Attitude magazine's managing director confirmed the news to the Mirror, adding: "We will have some exciting announcements to share soon."
And Kensington Palace said: "We look forward to speaking about this soon."
He and Kate met with LGBT workers at the US embassy in London
This isn't the first time one of the Princes have jumped to defend gay rights. In 2013 Lance Corporal James Wharton revealed how Prince William's brother Harry saved him from a homophobic attack.
Writing in his book Out In The Army, he explained: "I told [Prince Harry], 'I think I'm going to be murdered by the infantry.' I climbed into the turret and talked Harry through exactly what had happened. He had a complete look of bewilderment on his face. I couldn't stop the tears from welling up in my eyes. He said, 'Right, I'm going to sort this s*** out once and for all'."
According to James, Harry was then seen having a "heated" discussion with the six soldiers who'd allegedly threatened him, before assuring him he wouldn't have any more bother.
In the early hours of Sunday morning 49 people were killed and more than 50 were left injured following the shooting, which American authorities are calling the worst terror attack since 9/11.