In "Bodies that Matter: On the Discursive Limits of "sex""(1993) notable feminist thinker Judith Butler peaks up on her famous book "GenderTrouble" and her famous concept of perfomartivity. The notion that gender is a type of performance, something that some does rather than is, leads Butler to argue in "bodies that Matter" that bodies and gender are two separate thing. Divorcing discourse and social norms from biology, Butler deconstructs the thought that gender is something one is born with rather than acquired (like Simon De Beauvoir's "one is not born, but rather becomes, a woman" in The Second Sex, 1949).
Gender perfomativity, for Butler, is nonetheless not something any one particular person acts out but rather a ritualized socially constructed norm that one follows. In being a man you actually act out the socially sanctioned form a masculinity, the performance is ever replayed. Alas, there isn't one singular "act" of masculinity that one can perform in order to be the ultimate male. Gender is a form of discourse is something fluid and ever breaking down and reestablished , gender is not only done but is also constantly remade. Though constantly negotiated gender for Butler pretends to be "natural" and linking it to biology aids the gender discourse in doing so. Opposing and deconstructing gender rules and engaging is a subversive tactic aimed at exposing gender's artificiality and undermine its claims to being "natural" (like the example of drag queens discussed in "Gender Trouble". Gender, to conclude "Bodies that Matter", is just a norm and opposing is it serves to expose it as it really is, breaking it down and making it incoherent thus freeing the body from the constraints of discourse.
Some more classic Judith Butler and Feminist thought summaries: