I haven't been able to find anything on this, except Boswells book.
In 390 Christian emperors Valentinian II made homosexuality illegal, and even before that, there were laws somewhat against it.
I can find any other who backs up Boswells interpretation of Adelphopoiesis, Wiki has this to say:
The historicity of Boswell's interpretation of the ceremony is contested by the Greek Orthodox Church, which sees the rite as a rite of familial adoption, as the term adelphopoiesis literally means "brother making". [1] Boswell's scholarship has been assailed as being of dubious quality.[2]
Alternative views[3] are that this rite was used in many ways, such as the formation of permanent pacts between leaders of nations or between religious brothers. This was a replacement for "blood-brotherhood" which was forbidden by the church at the time. Others such as Brent Shaw have maintained also that these unions were more akin to "blood-brotherhood" and had no sexual connotation.
Edited by rbp, : No reason given.