Now before you read and answer i would like to invite you to keep the term "Sexism" aside as this is a discussion on gender and it is impossible to talk about it without pointing out some things that would look like stereotypes.
We all belong to some gender and if we write a paragraph and ask someone to read it and guess the gender obviously that person can identify the gender that is represented in that particular paragraph.
For example Men would like Bikes and women would like luxury cruse ships, Men would not give any attention to lighting when women would work hard to decorate with candle light because they think it is romantic...
And the list goes on and on proving that we Humans who differ from each other in almost every way tend to be so much alike in some things.
But how does this happen? Clearly no one would know the answer because if you ask some guy why did you started liking Bikes he would give many reasons but he would not be choosing a single answer to be the best fit as the answer, If you ask a girl why do you like Pink she would go trough the same situation.
Now we can suggest that all of these can be influences from the environment,Good marketing,Social factors and etc.
But then we end up with a question what exactly make "Gender" apart from a biological standpoint?
or in a much simple term,
Other than the body what makes a man and what makes a woman; Spiritually?
Now there are dozens of videos on the internet, people hypnotizing others to change the gender attached behaviors and it works in fact it can permanently change someones idea about his or her own gender.
After thinking about these things i came to an idea like this,
Gender as a spiritual part is an illusion. As Lord Buddha has said "Gender is also subjected to "Anatta / Anatman", Even gender can change according to the desires and actons of a being". So as to Buddhism you and i,we all have been in both genders and we all have even been "Transsexual". So as there is no "Soul" it is OK to think that gender is a post Birth process that we learn and act after. Because there is no point that we can show to say that gender is real.
Let me say one last thing before i rest my case....
Imagine yourself going through a Transgender phase, by the end of it you will end up in the other side of the river. Now you have a mind that functions according to the rules of your last gender and a body which resembles the opposite gender. Now what reason do you have to show for the love you have for your last gender other than the attachment that you have? I suggest that Gender is an acceptance that we make while we are alive to behave in a certain pattern. And because like anything else we get attached to it we carry it in "Samsara" until some circumstance change it.
What is gender apart from the body as to Buddhism?
If gender is subject to Anithya (Anichcha) + Anatman is it right to think of gender (spiritually),an Illusion?