These boy dancers, known as Kocek, became very well known from the 17th century onwards. They dressed in women’s clothes, grew their hair long & curled, wore kohl and danced in a provocative way. They were also considered sexually available to their male audience.  They worked in Meyhanes (taverns or nightclubs) and would regularly start riots with Janissary soldiers, who would try to woo them.

In the 19th century they were banned in Turkey. The boys then fled to Egypt, where the ghawazee had been banned five years earlier. The female dancers had been banned from Cairo, which then became the haven for the boy dancers.

Köçek on Wikipedia
“Dancing fear & desire” by Stavros Stavrou Karayanni
“Music and Gender” by Tullia Magrini
Belly Dancer’s Mind
The Family and the Society
The Male Dancer in the Middle East and Central Asia by Anthony Shay. JSTOR article.
Bacha bazi on the The Full Wiki.