A conjoined twin has revealed that he hid his true gender identity, keeping it a secret from his sister for decades, a report by Daily Mail said. Born in 1961 as conjoined twins, Lori and George Schappell from Pennsylvania had their skulls fused together and shared 30% of their brains.

The twins hold the Guinness World Record for the oldest-living conjoined twins. When they were born, medical science did not have a safe way to separate them. But even when the procedure was possible, they insisted on saying together. This resulted in the twins spending their lives joined at the head but facing in opposite directions and even pursuing widely different careers.

While they could not spend a minute apart, George hid a secret from his sister for most of their lives. Assigned female at birth, George came out as a transgender man in 2007.

"I have known from a very young age that I should have been a boy. I loved playing with trains and hated girly outfits. I kept my desire to change sex hidden - even from Lori - for many years," he said in an interview.

While he did not undergo a gender-affirming surgery, he dressed and introduced himself as a man. When he told his sister about it for the first time, she was shocked but quickly shared her support, saying she was "proud of his huge decision".