However, Butler argues, some ways of acting out gender norms implicitly or explicitly challenge the idea, central to the heterosexual matrix, that gender expresses sex. She uses drag as an example (Butler 1990a: 136-9). Men getting up in drag, doing the gestures and postures and wearing the clothes which signify femininity, shows that 'being' feminine is just a matter of doing certain activities. Drag shows that these activities can be done by anyone of any sex and need not be expressive of the agent's female sex. Drag thus reveals that gender is 'performative' - existing only so far as it is performed.
Another of Butler's examples is butch/femme relationships between lesbians. In these, the butch adopts conventionally 'masculine' attributes - strength, emotional awkwardness, protectiveness while the 'feminine' femme is caring and emotional. This shows that these masculine and feminine attributes exist only as long as people perform them, and that females as well as males can perform masculine traits (Butler 1991). Butler considers drag, butch/femme roles, and any other kinds of activity that similarly expose the performative status of gender, to be subversive. These activities subvert or undermine the matrix of assumptions that organizes our society. Specifically, these activities subvert the norm that males must act masculine and females feminine.