be one of the lads/boys/girls

be one of the boys

To be an accepted member of a particular social group, especially one made up primarily or entirely of men. Primarily heard in US. John's a nice guy and all, but he's just not one of the boys. As a woman working in this industry, you have to both be one of the boys while still being seen distinctly as a lady.
See also: boy, of, one

be one of the girls

To be an accepted member of a particular social group, especially one made up primarily or entirely of women. Jen's nice and all, but she's just not one of the girls.
See also: girl, of, one

be one of the lads

To be an accepted member of a particular social group, especially one made up primarily or entirely of men. Primarily heard in UK. John's a nice guy and all, but he's just not one of the lads. As a woman working in this industry, you have to both be one of the lads while still being seen distinctly as a lady.
See also: lad, of, one

be one of the ˈlads/ˈboys/ˈgirls

(informal) be a member of a group of friends of the same sex and a similar age, who meet regularly to enjoy themselves: His wife doesn’t understand that he likes being one of the lads from time to time.She’s never really been one of the girls. She much prefers the company of men.
See also: boy, girl, lad, of, one