It was a society-wide thing--because homosexuality was not supposed to exist, people gazed at all sorts of potentially homoerotic images without ever realizing how their behavior and interest could be construed. It still happens today, though less often--witness all the straight men swooning for "300" (and then hastily disavowing anything "gay" about the film or their interest). Sort of the same thing is happening in this panel from Batman 38--the dynamic duo seems to have traveled back in time to ancient Greece, so we got lots of Greek wrestling tropes, without any acknowledgement about ancient Greece being a profoundly pederastic society.