Femininity is

Traits such as nurturance, sensitivity, sweetness, supportiveness, gentleness, warmth, passivity, cooperativeness, expressiveness, modesty, humility, empathy, affection, tenderness, and being emotional, kind, helpful, devoted, and understanding have been cited as stereotypically feminine.

Masculinity is

 qualities and attributes regarded as characteristic of men. When we talk about masculinity, we’re talking about a person’s gender. Gender is a social construct, and is one of many ways we as humans make meaning and create social structures.

Binary opposites

Binary opposites are a pair of concepts that are opposite to each other. These concepts are usually thought of as a mutually exclusive which means you can only be one or the other. The idea was popularized in the 20th century by structuralist thinkers like Claude Levi-Strauss, who argued that binary oppositions are fundamental to human thought and culture.