If you are talking about men and refer to the opposite sex, you mean women. If you are talking about women and refer to the opposite sex, you mean men.
Body language can also be used to attract members of the opposite sex.
opposite sex in British English
noun
the opposite sex
In other languages
opposite sex
British English: opposite sex NOUN
If you are talking about men and refer to the opposite sex, you mean women. If you are talking about women and refer to the opposite sex, you mean men.