Ummm to make it not sexist I think you might need to add "thong" as an option for the girls.this time with more options (so as to not be sexist)!
...not only for the girls, I'd say, judging by most stores' men's underwear department here.Briefs and diapers.
Ummm to make it not sexist I think you might need to add "thong" as an option for the girls.