I think it is not just a Pashtun thing. It is an Arab thing.
Maybe not as obvious in some countries.
In fact, based on what I have read, all of the ancient civilizations were into this and quite open about it.
Bi-sexuality along with sexual abuse of children was commonplace. I am not sure when it became unacceptable in western Europe but it may have been as late as the Victorian period.
As disgusting as it is, I have read of certain groups in this country that are promoting pedophilia as an alternate lifestyle in the same vein as homosexuality.