There are scores of documents on Mehmood's sex life with the boy. If you refer to any historical accounts, that was the accepted norm of the pashtun society (esp high society). Mehmood was not Gay, but bisexual. Infact many rulers of afghanistan and current day NWFP of pakistan were bisexual. That's the truth and its left to you to accept or reject it.
Care to explain what 'sex' is? What was the sexual act which is even once documented?
It was an unusual relationship of master and slave with slave being very much a slave. There are no 'scores' of events documented.