Division between male and female organisms inside one biological species. As **sexual intercourse** it is an act of copulation between them. Wider understanding could be attached to eroticism.
Questions related to human eroticism should be marked with sex. This can refer to sexual behaviour during ages, relations between men and women (women's suffrage, feminism etc.), use of contraception, evolution of pornography etc.
For differences between man and woman clothes consider using fashion tag.