Authors' Note: Binomial expressions combine two paired elements in a fixed order. Lists of these phrases show that when the two genders are in question, males almost always come first. This bias is shown in dozens of idioms such as boys and girls, lords and ladies, men and women, brother and sister, kings and queens, Jack and Jill, etc.
The few notable exceptions highlight a gender-constrained role for women, including belles and beaus, bride and groom, and moms and dads.
Gender-bias in language is also discussed in another verse by the authors. Click HERE.