It's really not that complicated.
There is biological sex.
There is gender.
There is sexuality.
In a simple world, a male would be totally masculine and attracted to women. Women would be completely feminine and attracted to men.
It's not a simple world and sex, gender and sexuality are not all linked.
A man can be feminine and be attracted to women - he's straight.
A woman might be feminine and be attracted to women - she's lesbian.
I don't get the confusion here. Just accept that while sex, gender and sexuality are not linked, all of us sit at different places on each line.