Okay, those daggum homosekshuls, they even fooled me with their propaganda. :P
While the relationship of Achilles and Patroclus may or may not have been homosexual (very common and sometimes even institutionalized among the Greeks); during the time of Alexander such a comparison was bound to have such connotations.
So I guess the lesson would be that if you don't want such speculation of homosexuality about the close relationship between yourself and your lifelong male companion; you don't go around comparing yourself and him to two who were widely believed to be so.