Hi Vanda,
Wow! I'll admit I have not heard this
exact expression in AE, but I have heard the term "smarty pants," and it is
usually (though not always) used among children.
In AE, "smarty pants" can be used by and towards both men and women with no distinction. It is a name you call someone when they are acting or speaking in a sarcastic manner.
However, as I am not certain whether the "smart pants" you describe is the same as the AE "smarty pants," could you please give us a bit more context here?
I am also not certain if the usage among our BE-speaking friends is the same as that among AE speakers. Their "pants" are much different than ours!
👁 Eek! :eek:
Edit: I did a bit of googling. I did find a few references to smart pants that were about fashion and the use of certain materials in the making of pants (er, trousers to our BE bretheren) that help the pants maintain their shape after wearing. Is this what you are referring to?