We don't really think he should be talking about this...

Michael Douglas seemingly overstepped his boundaries during a Q&A in London on Sunday by revealing his former co-star Val Kilmer is battling oral cancer. The Batman star has denied he is ill, but has been spotted with a breathing aid and has been covering his neck with scarves in recent years.

The Basic Instinct star, who beat stage 4 oral cancer in 2013, let the secret slip while discussing their 1996 film The Ghost and the Darkness.

"The picture didn’t turn out as well as I hoped but I had a wonderful time. Val was a wonderful guy who is dealing with exactly what I had, and things don’t look too good for him," he said. “My prayers are with him. That’s why you haven’t heard too much from Val lately," he added.

The 56-year-old Top Gun actor has been insistent that his health is fine, though. "Thank you all for your love and support. There’s a rumor I’m unwell again and in hospital which is totally untrue. I was in to verify I have no tumor or infection of any kind which was verified by the very caring experts at UCLA," he wrote on Facebook in October 2015 after he was spotted at the medical facility.

We just hope he's ok!