男女
male-female; male and female
男女合校
see 男女同校[nan2 nu:3 tong2 xiao4]
男女平等
equality of the sexes
男女授受不亲
men and women should not touch hands when they give or receive things (citation, from Mencius)
男女老少
men, women, young and old; all kinds of people; people of all ages
男女老幼
men, women, young and old; everybody
男女关系
man-woman connection; intimate relationship
乱搞男女关系
to be promiscuous; to sleep around