The 'two-sexes approximation' is boolean, not binary. Boolean involves two possible values; binary involves an infinite number of possible values, represented in base-2.[1][2]
Not to be pedantic, but binary is entirely correct in this context. We aren't talking about computer science. Binary means relating to, composed of, or involving two things.
Boolean is simply a binary variable, having two possible values: true and false.
Boolean is simply a binary variable, having two possible values: true and false.