Pink, pink to make the boys blink
is an expression about the colour pink. Boys are not usually dressed in pink; it is considered a pretty shade for girls.
That will separate the men from the boys
describes a physical feat which requires the strength and/or experience of adult males.
You’ve mastered that may be said to anyone who has learned to do something well.
One man’s meat is another man’s poison is a saying about people enjoying different food.
Man to man is how people talk honestly.
A whistling woman and a crowing hen
Are good to neither God nor men
(or are neither fit for God nor men )
This expression is intended to deter girls from becoming habitual whistlers.
The female of the species is deadlier than the male.
There are some nasty women in history. Female spiders have a bad reputation too.
In short trousers used to mean under the age of about eleven years. Now even tiny tots wear jeans!
Who wears the trousers? Who wears the trousers in your house? These questions are about which spouse is dominant.