Gender again
It seems that there are two groups of people here (judging from discussions "which gender you prefer" etc.):
People who are more open with same-sex partners.
People who are more open with opposite-sex partners.
Personally, the set of things I can share/discuss with people of my gender is an exact subset of what I can share/discuss with the opposite gender. A romantic partner is the extreme (we can share romantic feelings - something I can't share with anyone else).
But there are some things I just wouldn't share with same-sex freinds, and they won't do this either.
Of course in a segregated society it is impossible to be this way. When men watch football and girls watch telenovelas - a girl and a boy can't discuss football and can't discuss telenovelas.
In sociology there are terms:
https://en.wikipedia.org/wiki/Homosociality
and
https://en.wikipedia.org/wiki/Heterosociality
and
bisociality

