If you ask people their opinion on gender, plenty will tell you that it is just a convention that science had to come up with and modern societies and people have the ability to change. There are people who are born as males and males, but like to dress like females. Cross-dressing does not change someone’s gender on its own, but it tells the world that being born one certain way, does not necessarily dictate the way that you are going to present yourself. Rules are only there if you want to see them.
In Zapotec cultures of Oaxaca in Mexico exists a third gender, called a Muxe, and refers to a male who opts to dress as a female.
Some of them are heterosexual, choosing to marry women and have kids, while others are homosexual, choosing men as their partners.
Muxes, due to their female presense, often stay at home and take care of their elderly parents, like women do.
Most muxe remain in indigenous communities, where they are accepted and aren’t treated as ‘weird’ and not normal.