The opposite of feminist is not masculine. You are conflating feminist with feminine which does indicate why your are maybe confused here. Feminism is not about being partisan like this, and you are operating through a strawman of so-called "second wave feminism" which is like over half a century old and defunct to everyone but guys who get angry at stuff like this.

Consider how calling yourself "atheist" or "rationalist" comes with some broad commitments and political tendencies, but not necessarily. We say we are an "atheist" to indicate a particular belief but also perhaps a broad attitude to culture as it stands, but not one thing or the other. Its like the same thing here!