no no, you got that mixed up. Harley's not referring to males in a feminine manner, he's referring to himself in a feminine manner. See, in English, our only forms of first-person (like "I" and "me") are indiscriminate of gender. In Japan, there are many ways of referring to yourself in first-person, even masculine and feminite ways (much like our third-persons are divided into stuff like "him" and "her"). Harley uses the first-person "atashi", a very feminite form. Aside from that, he also showcases his feminality by using the "wa" sentence particle to end several of his phrases.