Is it impolite to ask someone how much they weigh? Bag weight

I should say... I did not mean that I have to fit everything for my trip inside the Keepall - I'll have a checked suitcase too - I mean that I will have to have my wallet, phone, iPad, etc, everything that I would normally carry in my everyday bag, inside the Keepall along with additional items that I'll be taking on the flight. I don't expect to be able to fill a 55 to the brim and have it weigh under 5kg!
 
Does anyone know the weight of the LV Twist Tote? I am considering purchasing it in the grained cowhide but don't want a heavy bag. Any help will be appreciated. Such a great thread!