Which book did you read? I’m about half-way through “Gates of Fire”, Pressman’s novel about the Battle of Thermopylae.
For what its worth, lots of Ancient Greeks were also at least a little gay.
SnakeDoc
The idea of “being a homosexual,” as in “sexual orientation” as an unchangeable factor in a person’s makeup, is quite recent, probably less than 100 years old.
All cultures have recognized the existence of the “effeminate man,” usually with something between amusement and contempt. But the idea of a reasonably masculine man being “a homosexual” is novel.
Most cultures assume most men are on some level bisexual to some extent. In many, if not most, it’s not the gender of one’s partner that is of moral or honor concern, it’s the “role” one plays. The dominant “masculine” role is honorable, the receptive “feminine” role is not.
The Greeks, for instance, assumed upper-class boys would go thru a phase as “the beloved” of a considerably older man, then get married and have children, and then get into relationships with one or more “beloveds” of their own, while still continuing the domestic relationship with the wife.
But the Greek attitude towards homosexual acts is far more complicated than either side of today’s dispute generally wants to deal with.