girls undies 

to be viewed as weak or pathetic by your friend or group of friends for not doing as they suggest.

In extreme cases the put down can have "with skids" added to the end to emphasise the weakness/patheticness

"lets go to the pub!"
"Nah, not tonight !"
"YOU'RE GIRLS UNDIES"

extreme

"I think I am gonna pass on the pub tonight to spend time with my girl"
"YOU'RE GIRLS UNDIES... WITH SKIDS"

girls undies by Dale Kent June 21, 2008

Fly of girls dark blue panty undies. 

Which girls pee on the potty through which they wet their dark blue panty undies less, since when girls pee their unambulatory to take of their dark blue panty undies.

Esp girls under 10 will feel good of the fly of girls dark blue panty undies.

Fly of girls dark blue panty undies. by Turo Fernandez September 26, 2018